I use the cheaper Accu-Cycle.
http://www3.towerhobbies.com/cgi-bin...?&I=LXL357&P=0
The thing about a cycler is, not only can you use it to guage battery condition but cycling a battery that is starting to lose capacity can breath new life into that battery.
Some people will say they use a charger that shows how much is being put back in but that is not an accurate guage for 2 reasons.
1. you are not sure exactly how far the battery was discaharged to begin with.
2. charging is not 100% efficient so an accurate measurement is not possible.
Cyclers measure how much is disharged at a set rate after fully charging.