I'll add my perspective for what its worth.
I've had a
Pila since I got my first mod nearly 1 1/2 years ago. Loved it. You can tell by looking at it and holding it it is a quality item. It charged fast, too. When I purchased it I wanted the best, and at that time there was no other competition. I liked what I had read about the special algorhythms used potentially prolonging a quality batteries expected life. Well, I still have a couple of my original AW IMR 18650's in my rotation, nearly as good as new. 1 1/2 years of nearly every 4th day use and they still last me the entire day.
Sad but true, one of the bays recently stopped charging. The light turns red, with or without a battery in it, it seems unresponsive. It's now stashed away only for emergency use.
I needed another charger. Since I've accumulated many more mods, many more batteries of different sizes, I needed a multiple-bay charger.
I got the
Xtar WP6 II with 6 bays. It's a fine charger but I have some issues with it. My 18350 batteries keep popping out of the slots and refuse to stay in unless I lay something on top of them - that's a PITA. Also not a fan of flimsy springs in the slots - these springs makes inserting all sizes of batteries a PITA. Presently this charger only gets used 10% of the time, when I need an 18650 charged and my newer Intellicharger is full with other batteries.
Because of my ongoing frustration with the spring-loaded bays of the above Xtar, I got a
Nitecore Intellicharger i4. This has 4 bays and uses sliders, which I much prefer. I tend to use this charger 90% of the time. It see's 18650, 18490, and 18350 batteries nearly on a daily basis. I've had no issues with this charger and can highly recommend it. My daughter uses a Nitecore Intellicharger i2 to charge multiple 14500 batteries and she has not offered any issues with it.
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Concerning the
Pila vs Xtar VP1: As much as I love the Pila as a top notch performer, it probably should be updated to continue to be competitive with the new hot shot chargers like the VP1. The LCD of the VP1 looks nice and looks to be a pratical improvement, not just a bell & whistle. The Pila is just going on reputation now and will likely lose business to the new Xtar if they don't upgrade it soon.
Concerning the two chargers you asked about -
Xtar XP4 vs Nitecore i4, there's a difference of almost $10 between the two from the RTD listing. I can't tell much difference in features.
Battery chargers at RTD Vapor Both use the sliders in the bays that I prefer. The Xtar looks to only have the one indicator light for each bay to indicate charging status. The Nitecore uses a multiple LCD for each bay, it looks like a running board as a battery charges and then stays solid when finished, so you get more of an idea of the progress during charging. The Nitecore also indicates that it uses 4 completely independent microprocessors, I couldn't find that specification on the Xtar but it could very well have that too.
Unless I'm missing something, I think since they appear almost identical feature-wise I'd go with the less expensive Nitecore with no real reason to pay nearly $10 more for the Xtar.
