Re: To all you rack-mount guys out there...
I currently use a Mesa/Boogie Triaxis (2.0 with the Rectifier circuit), a TC Electronic G-major, and a Mesa/Boogie 2:Ninety.
I previously used an Eventide GTR4000 for effects and a Mesa/Boogie Strategy 500 for the power amp. For a short time I used a Mosvalve power amp after selling the Strategy.
Starting with the Triaxis, it's great. The sounds I get are simply amazing. If you can try one out, set aside some time. It does take time to dial sounds, especially since it has buttons instead of knobs to turn. Patience is well rewarded. I would also be careful with the Dynamic Voice and Master Volume controls. Those have to be used sparingly and balanced with the power amp or effects unit input to prevent clipping. Additionally, the stock tubes on the input seemed a little harsh to me, so I experimented and ended up swapping the input tubes for something a bit smoother to my ears. I prefer the sound of mine to the current stock models, especially since I can still break out Mesa Recto sounds as the newer versions do not have that circuit.
I switched to using the TC G-major since, as amazing as some of the Eventide's effects (the pitch shift and phaser in partciular) were phenominal, the unit took forever to program, required sysEx MIDI control, and lacked any good controls for gating functions. The TC sounds amazing. I have the parametric three band EQ and a very slow low level noise gate engaged most of the time. I have single CC command access to delay, phaser, and mute/tune functions. The Rocktron MIDI Mate pairs really nicely with program change to switch Triaxis sounds while using the CC commands to switch the G-major effects on or off.
The 2:Ninety, though less pwerful and a touch less full sounding than the Strategy, is a beauty. It is more crisp and modern sounding than the Strategy, has the Modern function, has a better switching scheme for deep and half-drive than the Strategy, and is way the hell lighter. The Strategy 500 weighed as much as a small dump truck, but did sound amazing. The 2:Ninety just fits my needs a bit better overall.
The main concerns with choosing a rack system over a combo or amp head are versitility and grounding, IMO. It's nice being able to have the majority of my effects accessable via one compact controller, though if you were to use an amp head, you could easily put everything on one pedalboard. Most amp heads cannot produce as many different modes as the Triaxis, save maybe a Mark IV or Mark V head. Remember to ground everything to one point; either use the grounds on the plugs and isolate the units from the rack rails, or use the rack rails and lift the wired grounds on ALL units. Everything needs one path to ground, no more, no less, or you will have months of hum, buzz, and shock risk.
Hopefully that answers some of your questions. Rack systems can be more complicated, mine is fairly simple; preamp > effects > power amp. It works for me, YMMV.
