I find the Snark to be fine.
Accuracy?....the guitarist I work with on a regular basis uses one, as do many musicians I work with in jam session situations, so we all typically are tuned to the same pitch. Seriously, I've not ever had any "pitchy" issues fretted or fretless in the eight or nine years I have been using one, in any stage or rehearsal situation.
I always carry an extra. Batteries can dump without much in the way of advance symptoms. Works....doesn't work.
Mine hears / senses the low B fine in most situations. However, in some rooms, depending on noise levels and what else is going on, it will take the Snark a little longer to "hear" the note and focus on it. When this happens to me, I do a harmonic at the 12th position and it gets it. If you're properly intonated, no problem. Usually when the note is sensed, the Snark does not lose it. My experience has been it is the first find on B that is the challenge. The solution is patience....maybe an extra 25 seconds....and using the harmonic. No biggie in my opinion.
Finally, someone mentioned earlier a price of $50. I bought several from Amazon for around $20, and have one or two that I bought for $16 - $18. So shop. You can find deals on these at Amazon and elsewhere from time to time.
Hope this is helpful.
Koog