I bought a Grind NTB 6-string for a project bass a while back. It was one of the later models, with the rounded heel carve.
The only real cons were cosmetic- you have to look for a good one, as the colour match between the body wings can be pretty random. Also, the finish had a couple of minor runs on the back and a few bits of grit and hair embedded in it. Thankfully, they rubbed out nicely with a bit of superfine sandpaper and some tung oil. Once the instrument was buffed up, it had a pleasingly boutique appearance.
The lumber, fretwork, hardware, etc. were all decent, and the overall feel and the fretwork were much better than I'd expect from a budget instrument. I liked the neck shape and overall ergonomics.
I wasn't thrilled with the stock pickups, but at $275 used, I could afford to experiment. With a used set of EMG 45CS's and a BTC tone control system in it, it sounded remarkably close to my good bass.
If you don't mind doing a little tweaking and setup work, a Grind can make an excellent backup (or a main instrument, if you're on a tight budget), for not a lot of $$$.