I am currently using AlibreCAD/AlibreCAM. I like AlibreCAD quite a bit, though there are some "warts". In short, it's not quite as good as SolidWorks IMO. If I had it to do again, I would buckle down and spring for SolidWorks.
AlibreCAD (just a flavor of MECSoft FOOCAM) is really trying at times. The default post file for EMC/LinuxCNC is pretty crappy, and I ended up modifying it heavily. It's path generation is also sometimes...odd. Overall, it is servicable, but if I had it to do over again, I think I would look at other options (Sprutcam maybe?).
I didn't review BobCAD, but I did look at Dolphin while I was trying to figure out what I was going to do about software. The sales guy was really helpfull, but it's drawing interface was more like AutoCAD; something that may be a bonus for some people, but I never spent much time with AC, and it is painful to me.
Most of these guys will offer a timed demo license (30 or 60 days). Best way to tell is to give it a try.