The problem I really have with it's inaccuracy is that it is not consistent; depending on what it is doing it will read differently.
It is still better than not having one, for purposes like testing to get charge or discharge graphs, but I feel like I have to sit and watch it when it gets near the end of either.
Mostly, I just wanted to point out that not all of these things should be trusted to accurately charge your stuff.
I suspect units like these to be a source of long-term pack damage from overcharge or overdischarge (if cycling for testing, for instance), that eventually result in some of the RC LiPo fires. With newer pack chemistries and better manufacturers, the packs can probably handle it, but with the older stuff that was less tolerant of any overcharge...well, you know.
Even the Battery Medics have been shown to be inconsistent. I suspect that part of the problem with some of these things is part tolerances not being tight enough, so too much variation from cell channel to cell channel, but that only accounts for units that have consistently inaccurate readings. For those like my Venom/E-station, it might also be in it's software design. I haven't investigated it, as there is little I could do to fix the problem either way. (no software skillz, and I have reached the point with eyes and hands that SMT work is almost beyond my abilities).