Unless you need the battery power get something else. Your acoustic is going to be about as loud as this thing. For 80-150 you can thigns that actually are guitar amps.
I had one that was kind of fun to crank up, but I am tube-amp poor so I ended up giving it to my son-n-law who uses it with great results as a harp amp.
From memory, Frank Z's trick was to put the opened up amp face up on the reflective floor and use a suspended SM57 2'-3' above the amp to record. By putting an open amp on the floor you are creating an infinite buffle or something loke that. Also recording it in a small space can work.