I'm really happy with new Boss GT-1. I also own Boss ME-25 (previous generation of compact processor in the same price range). The new unit give you much better sounds and functionalities.
- The biggest improvement in my opinion is a lot of various amplifiers with usable overdriven/distortion tones. ME-25 only had few usable amp models.
- Main speaker types available. Speaker simulation is engaged when using headphones of if you choose line output in settings (there's no dedicated line output, but you can simply turn it on/off in Output options). If connected to real amp, then speaker simulation is off but you still can select the type of amp you're connected to.
- All stompboxes models are on decent level - no complains. Modulation is great as usual.
- Different types of delays: analog, digital, reverse, tera echo. This is another huge improvement for me.
- The device is really compact and light. It fits to my guitar gigbag.
- New types of patches switching buttons with lighting. CTL1 button can be used to switch on/off stompboxes meaning you kinda have two patches in one.
- Boss tone studio is very straightforward for patches' editing.
There're only a couple of downsides:
- Wah sounds somehow plastic with overdriven tones but I guess it's quite typical issue in this price range.
- No power supply included.
Overall, great unit for the price - highly recommended. Just read manual before using, especially Output settings chapter (on third page of the manual). Also update system version to fix some program bugs. Upgrade instructions are available on Boss web-site.