Could someone please contrast between the Universal Audio 610 Solo and the old version of the M610? Other than the number of inputs and price, what is the major difference between the two? Time is of the essence due to eBay auctions where the M610 is located. I will need to buy the piece by next Saturday when I start recording guitar for my latest client. Any questions? Please ask. Need to be rude about something? I do not take things personally, especially from mods and revered members. Thank you very much!