I still prefer the CTEK over all others I've used (including Battery Tender). I have the 3300 and the 7000, and have been using them for several years. The 7000 is now the 7002, and it's the one I'd recommend. Amazon had them on sale earlier this week for $90. Given the features, that's a steal. Has a recondition cycle, separate profile for deep-cycle batteries, etc. Made in Sweden, very high quality. CTEK was the supplier for the Porsche battery charger (a CTEK 3300 relabelled). My CTEK 7000 is about to finish its 4th stint of being on the roadster for the whole winter (right now my battery is an Odyssey PC925).
2002 M roadster