I can see why some people might like Henkei Red Alert better, but the white arms are a big turn off for me now that I see it. Also take into consideration that the mold doesn't actually use red plastic, so his helmet quite obviously looks like red paint over black plastic. With that in mind if you want RA to have a show accurate red helmet, just buy the American one and paint it since the end result won't be much different.
Inferno is borderline for me. He's a brighter shade of red and has a lot of chrome, but I'm not sure that's quite enough difference to the Universe version worth bothering over.
Ironhide and Ratchet have at least 1 key thing going for them that convinced me to get the Henkei versions; no baby blue! The deeper red, side stripes, and chrome weapons are nice bonuses, but the use of blues that actually match the translucent windows was a big one for me... oh and that Ironhide doesn't have a blue face... and that at the time I got him he was no cheaper than the Universe version.
Lambor is... well he's Sideswipe with a few chrome bits. Neat, but not neat enough.