If ya want the best ya gotta pay for it. The POD modeller in your list. A 150 dollar J-Station won't keep up. If the POD sounds too dirty to you, then turn down the Drive control. The lack of a digital out on the POD hasn't been a problem since when I go down to the club and jam, usually the house mixers aren't using SPDIF's as inputs. And plugging directly into my Mackie board for further tweaking with the POD is more important to me for sound than a SPDIF line out is for me.
I've been playing guitar for years, I've played everything twice and plugged into a truckload of pedals and processors.
The effects on the POD are good side benefits, but not the selling point. The AMp modelling is top notch in the POD, simply the best you can get other than the real things. But who has access to over 32 different amps at 3am when inspiration strikes? Now I do.
I don't understand all the "the clean tones suck" comments. I plug my strat intot he POD witha clean Vox AC-30 setting, color it up, lay down some tracks and it sounds damn sweet.
Mind you, if your editing the POD on cheap headphones of course it will sound bad. A decent set of moniters, a good ear, a GOOD GUITAR- Not some Japanese lightning bolt from 1982, some time and using the Sound DIver software to edit with, you can come up with some Killer tones. Clean and Dirty.
And even if your not using it to record with, through a good house PA system, a POD will be a lifesaver instead of hauling around your marshall stacks to the local jam sessions with.
I'm a musician first, home recorder second. i don't care how good you are in your bedroom plugged into a harmonizer, I like to go the the local jams and cut heads with ym 6 string, and a POD has been some of my main weaponry....it will deliver in more than just a recording application. You can take this puppy on tour. I've seen a lot more Line 6 Pod's in the touring arsenal's of the big boys than I have J-Stations. A POD is more rugged and built solidly, you'd have to go out fo your way to hurt it.
Not to say thes eothers ones suck, Im not syaing that. for there price range there good. but if you want the best, spend the extra and get a POD. You'll be glad you did. The clean tones rock, The dirty tones rock, and the effects are there when your writing a song and need coloring, you got it all in one bang with no extra accessories or adapters to mees with. It makes for a real clean portable recording set up at 3am when inspirtaion strikes,
and its all about inpiration isn't it?