I have the Tonelab LE. I used it at first as a full function unit-modeling, fx, reverb straight into a power amp for gigs. It sounded very good that way, the best modeler I've used when compared to Pod XT Live, Boss Gt-8 and other earlier units. The LE since been relegated to use as an in-loop (bypass switched) fx processor so I can have different modulation fx and settings at my feet. It also does very well at this, the mod effects are great.
If you are set on a modeler, try the LE for sure. Of course, all the old amps sound great (don't they?), but do you want to gig out with some old dinosaur for which you paid several thousands of $$? Some guys do, but when a drunken schmuck spills his beer on your blackface/plexi/tweed treasure, you will be hating life.