16brae,
Here's my nickel's worth of free advice from my experience.
I've been mixing guitar tracks for the last 15 years. My first pieces of equipment were a Tascam 8-track cassette porta-studio. With that, I used a Tom Scholz Rockman direct and got a great sound for the equipment.
Once I made the venture into the digital world, I was first using a DSP factory with the Rockman, again with pretty great results.
After ditching the DSP factory (forcibly due to being disco'd by Yamaha), I switched to a EMU-1820m. The guitars started to sound very shrill and tinny, but still usable with some extensive EQ.
My troubles began when I dumped the EMU for some MOTU gear. I've been finding that the better the A/D converters (only an assumption albeit an experienced one), the worse the guitar sounded going direct. Especially the fact that the better the converters, the clearer the recording including the noise floor. Because of this new noise-clarity, I had to start using de-noiser plugins that kind of worked though not without their own set of problems such as, causing an unwanted flange type effect.
The guitars through the MOTU gear with the rockman just plain sucked and were unusable. I then tried the BOSS GT-6 and got a little more stylish crap. Sounds great live, sounds like a mess of noise direct. I then tried a PODxt. Sounded leaps and bounds better than the BOSS live, still an EQ nightmare direct. After this, I broke down and bought a PODxtPro rack mount. Still sounds great live or by itself, but trying to fit it into a mix has been the ultimate nightmare. Either winds up being way too bright or way too muddy, way to wide or way too thin. I won't even go into the buzz and AC noise issues. And with all due respect to all the cab-sim guys, to me they just don't cut the mustard and really color the sound more than I would like. I did have a few room problems, basically muddy-mix translations, which I incorrectly blamed on the bad sounding guitar tracks. After fixing most of the room problems (I'll make another post about this later), the guitar tracks still didn't sound just right.
Just a week ago, I broke down and decided to try the mic-the-cab approach. I first tried my Jazz Chorus-120 amp with a pair of Shure condenser mics, one up on first speaker and one down on second speaker. Got a pretty good sound though I really had to crank the amp for a good sound which being 120 watts was way too loud to be usable.
My latest solution: a Peavey Classic 30 tube amp with an SM57 angled at the cone going into a MOTU 8pre preamp then digitally via lightpipe to a MOTU 2408mk3. All I could say is "WOW". I'm so sorry I wasted the last 4-5 years on all those other direct/fake-cab solutions. That little Peavey/SM57 solution gave me a fantastic mono guitar track that is not only usable but truly sounds incredible. I added a little compression and a few touches of EQ and widened it a little with Sonar's Channel-Tools and wound up with a big bad wall of guitars sound that sits in the mix just like I wanted. For the lead guitars I recorded harmony parts and just panned them 50% left and right respectively and got some of the best sounding guitar tracks to ever come out of my little studio. I'll post the tracks once they're completed.
If you've got an amp, do yourself a favor and go get a new SM57 for $100 and try it. My next two tests are going to be my Marshall for kicks and grins and I'm probably going to try and pick up a 15-wat 1x12 combo just to be able to get some more gain and sustain at a little lower volume than the 30-watt.
Hope some of this helps and good luck with your tracks.
Best,
Guitardood