I have a Poolmate Pro.
Does exactly what it says on the tin, counts laps pretty well, only ever 1 or at most 2 out, not that I count as well but sometimes youll stop for a rest at the 'even' end of the pool and an odd number of laps will show, 25 metres out in 2k aint bad.
The pod thing is way over engineered as is the data displayed once downloaded, but filter the data to get what you want, efficiency SWOLF score, stroke count, distance whatever.
Got mine second hand on eBay £54.