I've had mine for about three years. It's pretty reliable in reflected mode and I like the fact that the needle doesn't jump around widely, which happens on some meters.
In incident mode, I've been less confident in the readings but I really need to do a proper comparison with my Sekonic L758 to assess the accuracy of the twinmeter in incident mode.
I moved on to the L758 (spot + everything + makes the tea) because, apart from the spot function, I wanted a meter that would measure at lower light levels. But it's not fair to compare the two meters because the L758 costs about four times as much as the twinmeter. I still carry the twinmeter occasionally, usually when I'm likely to be handholding the camera and also want to be relatively inobtrusive. In fact I wish the L758 had the averaged reflective function that the twinmeter has - you can't exactly whip out a grey card and place it in the scene if you're doing street photography.