I guess it depends on what you think is a 'good' tone. Personally, I've usually found that using POD's for recording crunch-overdrive tones sounds a bit thin in the mix (compared to real tube amps). I usually use them for scratch tracks & then go back & use real amps & multi-mics to get the sounds I'm after.
The best use (in rock) that I think I've ever heard coming out of Line 6 stuff was on Chris Cornell's solo masterpiece, 'Euphoria Morning' which featured the amazing Alain Johannes & the equally great band Eleven. But I'm sure whatever Line6 stuff they used was mic'd up real nice & sent into a few channels of Neves or API's. It wasn't POD setting #11 (or whatever).
I bought a POD XT in the hopes that it would simplify some live playing situations for me. But the difference in tone between plugging str8 in & going thru the XT has made me relegate it to studio use (mostly as a tuner & scratch trax). It has cool modulation & delay stuff, but the amp models sound thin (imho) & the distortion pedal models are nearly useless.
POD's CAN BE cool, for clean tones that are more JC-120-ish. Or dirtier tones used in concert with already established tube tones in a recording.
If you are limited to recording your guitars direct because of volume concerns, might I humbly suggest that the cheapass original Behringer V-Amps (to my ears) sound a little more like mic'd up real amps in a track, than almost any of the POD stuff. You can get one for about 40 bucks on ebay. I've gotten fairly decent direct tones on a few tracks using a V-amp with a yellow POD multi-dist/ovdrv unit (usually used as either a clean boost or the colorsound tone bender in front). If you want to hear a bit of this v-amp in action, I have 2 older tracks up on my garageband page, titled, 'The End' & 'Dragon Killer', although on those tracks I was going more for kinda Queens Of The Stone Age & Alice In Chains sounds rather than an EVH-ish tone on either
http://www.garageband.com/artist/mostdangerousgames
to sum up.. POD's can 'kinda sound' like lots of things, but much like many recording plug-ins boasting vintage tones, when you put it up side by side against the real thing, there IS no comparison.
I hope this helps.:banana: