I went out and bought the 75 watt version today. I was there asking about it before Guitar Center was even able to unpack their delivery. I played with it for long enough in the store to see that I wanted it. I got it home this evening and started checking out every amp and effect one by one. When I got to the Mod effects I noticed that when I changed effects, nothing was happening sound wise. I am using an iPhone 5S ios 7.0.4. I made sure all apps were closed and tried again and still the effects were not changing. I did a hard reboot on the phone and picked up where I left off. After making a few changes, the sounds stopped changing. I started poking around the app and found that it said it was not connected to the amp. I checked the bluetooth connections in the phone and it said it was connected to the amp. I opened up the music app on my phone and started a song and it was playing through the amp which proved the phone was synced to the amp. Problem is that even though the connection between the phone and amp appeared to be solid, the app would lose connection with the amp. Doesn't make sense unless there is a bug in the app.
I will say that the amp sounded great, as long as it was working properly. I even ran an 8 string through it and the 8 inch speaker handled it without a problem and it didn't sound muddy at all. I didn't crank it, but at a low volume it sounds great.
This was my one fear with this amp. If you have problems with the app, you are dead in the water other than the 4 presets that are in the amp itself.