I dragged a GK MB150 around Seattle for years. I loved it for what it was. It felt like a good tool for the job and was reasonably inexpensive on the used market. It was solid and reliable for me, but it did carry heavier that I felt like it should with and without a bag. Might have just been the kind of flimsy handle. It was a miracle in its day and still small, but not really light by today's standards.
It also didn't handle every situation for me equally well. Good room, good tasteful band, it was great. I used it and left it as backline for the next group in a medium sized auditorium once thought it filled the room beautifully, but good acoustics. Some bars, some drummers, I fought it to work for me. I'm better with eq than I was then, but still I think it had limits.
I also had one of the AI combos after that. It is more modern and worked exactly as it should. But, as someone else mentioned, the shape made it not carry as light as you might expect. If you were empty handed and using both handles it was probably fine, but one trip from the car, with the bass on your shoulder, I really didn't enjoy transporting it, which was kind of the point. Like the GK it also worked well in some settings and just didn't get it done for me in others.
I've determined (gonna make some enemies here) that I really don't like the AI pre-amp voicing. I don't find it to be neutral and I have struggled to fix that, even with my improved eq skills. I have a head now and it's great with a q\Strip in front and plugged into the effects return.
I almost bought an old 200MB last year, it sounded great, but had a rattle and say what you will, newer equipment has been quiet and reliable for me, I don't want to chase gremlins or worry about my gear on a gig.