Re: Tascam trainer?
IMO, yes.
But, it should be noted the Tascam trainer I'm comparing it to was one original releases, and had a CD player, not the MP3 you're considering or like on the Boss.
I did have trouble with Tascam's menu's. While fewer buttons appears to be simpler, it was actually confusing toggling thru all the functions and menus. It was especially hard to tweak any of the pre-programmed effects. The boss was by far easier to use.
The Boss also blows away the Tascam on features. Not only is the Boss a trainer with built in guitar effects, it also has:
tuner
4 track recorder
built in mic
input for external mic
voice cancellation
metronome
over 300 drum patterns, each with beginning, fill, and end.
There's probably more that it can do that I can't remember.