it all depends on the situation...
i'm just adding my 2 cents worth to the forum. i really agree with all the posts above though. i actually own the j-station, pod, and bass pod and use the j-station over the other two for guitar and bass (it has, uh three or four bass amp models and three cabinet models).
the j-station has a spdif output that makes its the hands down winner for sparkly clean tone like a mid-driver
jtm 45 (i think that's it), also, big point for me, may or may not matter to you but the j-station's computer interface software is much much much easier to use than the pod's. i've owned the pod's for several months and have yet to figure it out (and i'm pretty midi literate) where as i was editing the j-station the day i bought it. the guitar pod does have some really nice dynamically responsive amp models though, the pod-drive and the blues amp models really act like an overdriven tube amp and it sounds very convincing when recorded. but nothing out there hangs with the j-station's dual rectifier model, it records like a marshal stack with a pro engineer working the mics and board, it's unbelievable, try it out. i still use an old amp/cab live, so i can't comment on any live uses, but for recording, if i had just one, it would be the j-station.
oh yeah, i have played on all the digitech competition,
rp-100, 200 and 2000, they sound like crap through an amp, i tried and tried and couldn't get anything but crap and more crap out of them, maybe they work better in a studio, maybe... well, hope this helps you, i'll check back here, so just post if you have any specific or special application questions about any of those three models and i'll try it and let you know...
Capt. Snazzy