The H3000 series are now all obsolete. The Eclipse replaces the H3000 and is much more powerful, offers improved effects, Converters, MIDI control and has full digital I/O. And although the Eclipse is now the direct replacement for the H3000 series, it is really a more scaled down and limited version of the DSP7000. The Eclipse offers more DSP power than in the DSP4000 series, but is not as flexable in the effects creation/editing/routing.

The H3000 is still a great unit and has value but is just more limited. Eventide will very soon drop all repair support for it and since they are really the only ones that can do repairs, that is something to consider. The H3000 series also has a full analog type sound that is different than the newer units and is a very big part of it still being a much desired unit. There are a few special algorithms that are unique to the H3000 that can't really be duplicated on the newer units.

The newer units, Orville/H8000/DSP4000 series/DSP7000 Series offer many times the DSP power, flexability, hundreds of useable presets and almost endless unlimited options to do amazing things in audio processing.
The DSP4000 series (GTR4000/DSP4000/DSP4000B/DSP4500) are also now obsolete and are replaced with the much improved and more powerful DSP7000/DSP7500 and the dual processor multichannel units Orville/H8000.

If your into major effects tweaking/customizing or if the flexability of custom algorithm construction is something that appeals or may be something you need then any of the units except the H3000 series or Eclipse will serve you very well while those two will serve you very well just like many of the other standard effects units that offer a fixed number or presets but with the Eventide uniqueness.