Personally.
Its a nice feature the trickle charge, I would suggest that a charger that is microprocessor controlled. A lot of the cheaper chargers often employ a pass transistor and resistor to select a lower charge current,
Its all good , but heat ,frequent use ,can degrade what will most certainly be cheap capacitors,..and after a while the trickle charge with slowly cook the cell or battery, simply because the charger runs out of its parameters.
just my experience ,after purchasing a name brand battery cooker ,I prefer a microprocessor controlled unit..
The microprocessor units are often quite cheap , theres no heavy iron core transformer and use mosfets .. this results in better more precise current regulation.
http://www.ti.com/lit/ml/slyp089/slyp089.pdfcharge options can include , NiCad,NiMH,PB,SLA,Lipo,LIon..
I use a cheap little unit , iMAX B6AC .. It does what I need.
Hopfully other's chime in so you can make a better educated decision, battery's are not getting any cheaper. the more life you can squeeze out the better.