So, I'm a few weeks into building, tweaking, and using the pi-stomp and wanted to provide some overall comments that might help others.
Pros:
1) This pedal is simply awesome. I mean awesome. If you like building effect or any electronics really (and play guitar), its one of the best I've ever made.
2) It helps if you know a little Linux if you want to "tweak" stuff. I also had to do some debugging and knowing what little Linux I do helped a lot. You could probably do the same with a text editor using a Microsoft product. But I'm an iMac guy and use the Terminal app exclusively, so I can't speak to that.
3) The unit seems to be very low noise, even using some of the compressors and distortion pedals. I have a very complex pedal board with a long signal chain and I found that the distortion effects were much more quiet than even those emulations built into my amps. This includes some fuzzes as well. I don't have any test results so no measurements were taken; just my ear. Maybe you won't have the same experience, but I suspect you will.
4) I can't detect any latency. It might be there if you build some complex pedalboards, but I haven't had any problems. Compared to my EHX Pitchfork, the Pi-Stomp seems to have zero. I know this isn't true, but for what I do with it, I can't detect any [latency].
5) I found support to be pretty dang good! No, you won't get instant answers as these guys have day jobs. But I didn't have to wait days either when I had some technical problems. In fact, I was helped with an "add-on" Midi controller I built into my pedalboard that added 8 more switches using an Arduino Teeny computer - they even helped me with some code for that controller and it had nothing to do with the Pi-Stomp.
Cons (very minor)
1) Probably because I'm thick-headed, but the instructions for everything you might need to build and tweak were across multiple web pages. This includes the build of the OS (github). Jumping around via different links was a little bit of a pain (I eventually just bookmarked them - should have done that early on!).
2) I was missing a couple of spacers and had a couple of extra bolts. Not a big deal as I have spacers on hand. Lots of parts in this kit (and to be fair, there's no QC department with paid assembly folks), so sometimes minor things like that get missed).
3) The web interface can be a little glitchy - this isn't on Treefallsound at all, but something to be aware. Again, this was minor as I never lost anything boards I was building. But the dang thing would sometimes not update or would randomly disconnect from the Pi-Stomp.
Recommendations for all builders
1) Get the enclosure. Its VERY well made and all the electronics fit into it perfectly and very professionally. It would have been a royal pain to make this myself out of some aluminum Hammond enclosure. I've made tons of pedals and drilling a couple of holes for pots, a stomp switch and some in/out jacks is super easy. But the Pi-Stomp has a screen and jacks that really need to be precision measured and cut if using your own enclosure. Unless you've got the tools and have done that kind of thing before, I really don't recommend it.
2) Build with the LCD below the enclosure and not protruding up. A little more work, but worth the effort. It just plain looks better.
Recommendations for Mods:
1) Add a plastic window that would protect the LCD display.
2) Add the ability to assign banks/programs that can be addressed via a midi controller. In that way you aren't picking a pedal board and flipping through presets, you could just hit Bank A - Board 2 and then use the midi controller and PI-Stomp switches to turn off/on effects. I know this would be pretty dang difficult, so I get it doesn't have that functionality. NOT a deal-breaker at all. I play in a cover band that performs a HUGE variety of songs. I don't actually flip through boards much if at all as I can get the effects I need with one or two boards/snapshots. But I can see some folks who would really like this.
This is a very impressive piece of hardware, buts it is NOT for someone who isn't familiar with building these types of kits. If you've built several footpedals in the past, you're probably in good shape (MUST be compentent with soldering). I've done that kind of thing plus some digital builds like a cable TV decoder and even guitar amplifiers, so for me this was easy.
Overall I can't see any guitar player not falling in love with it.
Hope this helps!