I recently bought a Guild B-240EF. Happy to share my thoughts. Context: I'm an intermediate level player. My main bass is an electric Yamaha BB2000. I'm into blues/country/folk/rock/soul. Once a week I jam with two guitarists and a harmonica player; we do occasional low-key gigs (5 or 6 this year) but mostly we just like to get together to make music for ourselves. One year ago I bought an acoustic Sigma BME+ to play at home unplugged along with streamed music. At first I didn't feel super comfortable with the Sigma, but it grew on me and now I love it.
Now, the problem with playing along to streamed music is it isn't always standard tuning, and when a song comes up that's slightly sharp or flat, I don't want to re-tune my guitar: I just play slightly out of tune or skip the song altogether. The solution, I decided, would be to go fretless. However, my technique is not perfect: I've never really tried to place my fingers just behind the frets like they say you should. Especially down at the low end, when I stretch 4 half-steps (happens a lot) my pinky is just barely clearing three frets. So going from fretted 34" scale to fretless I figured the B-240's 30.75" scale would have fret-lines close to where I actually put my fingers. It turns out I was right. With this scale I can leave my index on the first fret line of a string and put my pinky right on the fourth fret line. Muscle memory from playing a 34" fretted with sub-optimal form translates perfectly to playing 30.75" fretless ! So as far as now having a fretless acoustic I can play without having to think about fingering, success. I want to say to anyone nervous about switching from fretted 34" to fretless: going shorter scale was a good idea for me. I was concerned that the strings would be floppy on shorter scale, but it turns out the tension is just fine.
At first I didn't like where the bridge is placed. It is relatively close to the sound-hole, and when you hold the guitar on your thigh and naturally drape your right arm over, the plucking hand wants to go right on top of the bridge. After some experimenting, I found that by using a long strap and kicking the tail out to my right, my hand wants to pluck over the hole, which seems to be the sweet spot. Also, doing this angles the neck up and brings the lowest notes closer, both improvements over holding the guitar on thigh with neck straight out level. So: I recommend using a long strap.
Sound: unplugged it plays at about 45-50 dB (I got an app to test it). It is just loud enough to play along with streamed music. I like to listen to my music in the range of 50-60 dB. Sigma plays unplugged slightly louder, right around 50 dB. I do wish the B-240EF was just a few decibels louder unplugged. As of now, the B-240EF unplugged is far too trebly for my taste; it sounds thin. The Sigma is definitely bassier. However, I recall I didn't like the sound of the Sigma at first either. They have exactly the same strings. So I'm thinking the bronze strings maybe mellow with age. I'm going to give it a little while.
Plugged in this bass is awesome. Where the Sigma tends to cause feedback, the B-240EF does not. Turn the treble all the way off, crank the bass and the amplified sound is amazing - with a kick-drum thud on each pluck. I love it. In fact, it might become my main bass. The Sigma amplified is also more percussive than the electric Yamaha - must be a thing with the acoustic body + piezo pick-ups. The B-240EF hits a lot harder, though. My theory is that it is due to the placement of the bridge. The Sigma's bridge is back further from the sound-hole. I understand that due to the X-bracing, a bridge closer to the sound hole is on a more rigid part of the top. Could be something similar to the difference between 12 and 14 fret acoustic guitars, where, I've heard, the 14-fret tends to have a tighter, snappier attack because the bridge is closer to the sound-hole.
I hope this helps someone thinking about buying a B-240EF. Also, if anyone understands bridge placement and its possible effects on sound, I'm all ears.