I'm using a Mackie SDR to track on, mixing in Sonar. I'm happy with it, as are my clients. The main advantage over the HDR (besides cost) is it will support extremely large ( 2 Terabyte) hard drives. The HDR has a 32 Gig drive limit. I just put a 120G drive in mine. It has analog or digital ins & outs, ADAT sync, SMPTE ports (read only). I haven't had any maintenance or performance issues to date.

The Alesis HD has proven it's self as a good unit but still has a few issues. The Tascam is very good and more mature unit that has more features/options. Not used the Mackie, but have heard many regrets from users who do own them.

The Alesis is very easy to use ...

The Tascam has a more difficult learning curve but offers more editing abilities.

The Mackie, I haven't used .. so I can't say. Suposedly you can take a HD right out of it and put into a computer to import / export projects.

I have heard the Mackie and Alesis, but not the Tascam.

If you have the extra money, invest in a RADAR 24 with the Nyquest converters.

Just my 2 cents, but first time I heard this machine, I was a believer. We ended up buying one, havent looked back since..

Another vote for the Radar, but I wouldn't make the Nyquist converters a requirement: the standard converters are very nice and a great deal. However you get the Radar configured, you will Never regret having spent a little more than you would have on the decks you mentioned. The Radar was a good deal when it was 5X its current price; at $5k, its amazing anybody buys the "competition."

Seriously, sell something, borrow some money, eat less.....do whatever it takes to upgrade to a real professional recorder.

Not to beat this to death.... RADAR 24 is a cut above... Throw in the fact that IZ corp (who makes it) has rock solid phone support...

Also, the machine has not crashed on me once during a session... it runs BE OS (operating system) that was designed from the ground up to be a stable recording platform...

If your not convinced, go to their website http://www.izcorp.com

find a dealer in your area, setup a time to go in and hear the unit and you will be a believer... !

Also, read the reviews.... Many Studios are now replacing their 2 inch tape machines with these units....
Also, Pro tools studios spend the money and just use the Radar 24 for its converters.... because they are superior to what you get right now with PT systems... !

BTW - I am not paid by, endorsed or affiliated with IZcorp in any way...

What are you waitin for.... Go hear one ! 8-)

Another vote for Radar (anyone running 3.30 yet??). Nyquist is undoubtedly nice but the Classic converters are simply incredible.

Ulitmately, which unit you get depends on your budget and your needs. The Alesis units seem to find a home with people who want decent conversion but will fly the tracks into some kind of DAW later for editing. The HD24's do have some basic editing on board but it's destructive and can't be done with mouse or keyboard. Don't know much about the Tascam's but I've heard they're pretty solid units. As I understand it, they have a bit more onboard editing than the HD24's. I've heard both glowing reports and horror stories on the Mackie's. They appear to have the most onboard editing of the the three. If memory serves, you have to purchase the interface cards separately and they can be a bit pricey.

With the Mackies, you have to purchase 8 channel I/O cards for the HDR, but the SDR comes with with analog I/O cards standard. Since I'm using an analog board for inputing signal, it made sense to go that way and save $1,200 (which would but a 2nd SDR) in cards, $4,000 overall. I'm told the converters in the HDR are better, but I'm not unhappy with the SDR converters. I copy files to one of several external drives and place that drive in a firewire case, BAM!!!! into the DAW for work in Sonar. Editing is destructive, but once you learn your way around the keystrokes and ask the client 3 or 4 times if they want to save that last take, you save or delete accordingly. I purge the project before exporting, which pares down the files that get transferred. Then it's a snap to assemble punch takes to their appropriate master track in Sonar. Nuthin against RADAR, great gear, but as mentioned, a matter of budget.

I have an SDR that I use mostly for remote recording, and an MDR in the studio. As mentioned earlier, the SDR comes loaded with all the I/O options built in. I've been spec'd that the converters in the SDR are inferior to the MDR. I haven't been able to really notice that. The MDR, as mentioned, does require purchasing I/O cards, so that's a few bucks.

The Alesis uses an allocated memory storage technique, which renders it more like a linear device when recording. Because of that, you can't keep virtual takes. I think the Alesis is a good unit for live recording, where it's "RECORD" at the beginning and it just rolls till the end (no punches or dubs).

The Mackie products allow virtual takes that can be accessed quickly, but also stores EVERY take which you can get to if your crafty. The Mackie products store their sound files as time stamped broadcast wave files, which can be imported directly into most DAW without any conversion. The Alesis product stores their files in a proprietary format that requires a conversion step for most DAW's.

I use my MDR in unison with my Pro Tools setup and it works flawlessly.

The MDR/HDR from Mackie are built like tanks, the SDR is slightly flimsier, but, what do you want for $1200?

I have no regrets with either my SDR or MDR...

Hope this helps...

Another positive report for the Mackie here: I use my SDR for my remote gigs, and it's been flawless in the 9 months I've been using it; plus I go straight into it using the ADAT inputs and feeding it with the A/D of my preamps, so I bypass its converters, and the sound I get it's nice and clear; obviously higher end machines like the Radar will sound better, but I think for a budget conscious choice the Mackie at $1200 is a great value, and it's solid enough to be carried on the road (I have it mounted in a 8 RU case with preamps and mixer) for location gigs; plus I mounted a removable drive tray for the external drive and I can then load drives up to 1 Terabyte in size (currently using a 120Gb) that I pull out and plug into my Pro Tools rig for editing and mixing of the tracks: works flawlessy back and forth.
The SDR has all of the features needed to do pro work, like analog and digital I/Os, SMPTE, MTC, Word Clock, BWF file format, USB hub etc..if you have A/D conversion already the machine will only act as a recorder and it is flawless (despite a few first serie units that had issues). The A/D and D/A conversion is obviously not at the same level as that of Radar or Tascam machines (this last one I worked with personally, after a few bugs in the softawre have been worked out it's a solid pro machine, but has a steep learning curve, the SDR is plug and go just like an old ADAT or DA88), but I think that eventually clocking it to a good source could improve the quality of the conversion in a noticeable way.
Can't talk about the Alesis.

In the end I think that if that's your budget range the Mackie is a good deal.

L.G.