i have the:
nitecore i2
nitecore i4
xtar vp2
xtar vp4
luc 4 bay
i use the nitecore;
i2 in my personal vehicle and only when necessary
i4 for AA and AAA rechargeable batteries solely
they have a fair share of their glitches and often under charge my cells. also they can't recover a cell that's been overly discharged like the others can.
i use the luc in my bedroom by my side of the bed because the wife has a hard time with the way overly stiff sliders. also because she has smaller batteries that simply cannot be charged at it's minimum charge current setting of 0.5 amps. it's less versatile and less accurate than the xtar chargers, but worlds of hurt better than the nitecore lineup.
i use the xtar;
vp2 in my truck because i live there on the road and i need something dependable and accurate with a flawless safety record. my truck...
vp4 on the wifes side of the bed so i don't have to worry about her and my childrens safety while i'm half way across the country, the sliders work perfectly and they're forgiving on her delicate nails in comparison to the other brands, it's completely accurate giving her the most run time safely possible on every single charge, it has 4 bays so she can charge her smaller paired batteries and larger batteries at the same time and lastly, the display keeps her from calling me questioning me about simple things that likely don't matter much... especially since some of her batteries are paired and should be at the same charge state when used.
if i buy any more (and i have for other people), every single one will be an xtar. (i hate the idea of using/storing/finding spacers, so pila isn't an option for me... nothing else against them, but i've never used them, either)