I found the Line 6 HD300 to be really powerful. It has the DSP power in its hardware, and, the Line 6 firmware is also awesome. There are online patches available through the usb interface on their website and it even has a wah/volume pedal. They can be found cheap also. The hd400 and 500 series are even more powerful with the 500x having an XLR microphone input with line and xlr as well as usb in and out.The pedals also have dedicated loopers. If you go in and edit your stomp box and amp modeling presets you can really personalize it and back everything up with the computer librarian as well. Very stable drivers. Did I mention its cheap used and sounds really good? Even though they have new ones out, I found all I had hoped for with the HD300.
Here is a link to a demo. The HD300 just cannot chain as many stomp box models together and you do not have individual tweak knobs available all at once. So like most stop boxes on a pedal train you have to put a little setup time getting "your" sound. Then save it to internal memorry or the computer. The 400 and 500 have more tweakable live controls. But I have not had any desire to upgrade even though Line 6 has new helix stuff out. It would be like trying to get a new tube screamer when you already have 8.