What are your goals for amp simulation? I have a Zoom G5 and I'm very happy with it. Great Fender and Marshall amp sims, but my favorite is their Two Rock Emerald sim.

The Z-axis pedal lets me use pretty much just one patch for a 5 song set.

Also, you won't find any amp sims/multi-FX that have time multipliers for the tempo. For example, you want U2 dotted 8th delays, you tap in 1/4 notes and if you have dotted 8th picked for the time multiplier, it's there instantly. I shopped hard for this feature because many of the songs I'm required to play live use dotted 8ths. You'll pay easily a couple hundred dollars more to get this feature in any other device.

So, what is your goal for going amp sim with multi-fx?