i have a cdr-5k and a protrak and both are sweet. IMO the cdr is a hopped up protrak. both charge so well and both can give the same data.
bottom line if you have the budget you should go for em (protrak,cdr5k,gfx). you cant go wrong with any of these chargers.
one more thing as long as you purchase a charger fom a big name company(novak, lrp, integy, etc.) youll be fine.