Having been spectacularly dismissive of the MFG (Muzzle Flash Generator) and slightly bemused by the SMG Rattle, I was rather intrigued by the new Incentive Designs (henceforth ID - I really can't be arsed typing all that out) Tracer Mags.
As a bit of a CQB freak I've been using a couple of tracers for a while (the B&T one and a QD Dytac one) both of which have been very effective but rather ungainly (especially the Dytac one stuck on my SCAR - makes it just that bit too long for running up stairs safely). I have an old G&P tracer mag that got used a few times but just wasn't all that bright. Having seen a review by a buddy of mine the new ID ones seem to use much brighter LEDs (technology has come a long way in a year or so) and having chatted with him they seem to be much better.
So ID started selling Pmags modified with their new guts for £65 incl postage on ebay but 1) I don't like Pmags 2) they won't work in my AK and 3) I didn't want to pay that much for a tracer mag! I got in touch with Kev at ID and he offered to modify a couple of my own mags for £45 each including return postage so off went one G&G metal hi cap and a Cyma AK74 hi cap.
They came back ina adecent amount of time and I finally had a chance to do a side by side comparison last night. The main difference in function is that the ID mags have a small slide switch on the side to turn the UV LED on and off meaning you can turn off the tracer function and still use the mag as a standard hi-cap. They use a micro LiPo battery and come with a small USB charger that lights up red while charging and blue when complete (not sure if it auto shuts off though).
To the naked eye the ID mag LED is MUCH brighter - easily more than double the output of the G&P one.
In use it certainly makes the tracer glow much brighter, not as bright as the silencer types but certainly more usable than the G&P. Granted the first few rounds will gradually fade in the hop unit so if you're a dedicated single shot sneaky ninja these are probably not for you (but then you probably won't be using hi-caps anyway).
I've yet to properly skirmish the mags but I'll certainly report back with my findings (and hopefully some video if I can find someone with a decent camera that will pick up the tracer).
TL;DR - yeah, they're pretty good!