I have an RQ2314 for live use only. I don't think it's very suitable for studio use. The pres don't have a ton of gain and aren't very linear at the higher end of the range. I haven't done a critical comparison with my other pres so I can't really describe the character of the Peavey beyond that.
I like it a lot for live use, it's very intuitive and I can explain mixing to a layperson very quickly which I have to do rather often.
If you do use it in the studio, you've got six sends (L/R, Mon 1, Mon 2, Eff 1, Eff 2). However Eff 1 and 2 are post fader so you effectively only get 4 separate mixes. Mon (pre-fader) and Eff (post-fader) sends are not switchable pre-/post-fader. If you need six sends, you can set the faders to like -30 and crank the Eff sends all the way up. You'll get a little of the Eff mix in the L/R but it's not too bad.
There are channel inserts on each channel so you could go that route if you don't need to submix. That's probably your best bet as then you can use the L/R for balanced monitor outs (connecting your computer audio outs to the Tape In) and you'd have two headphone mixes available via Mon 1 and 2--or three, if you used the Mono out too.
In summary, there are better choices like the Mackie which manages the aux sends better and has better pres, but the Peavey will work for basic signal routing and submix duties.