JVC RS15 vs. SP8602 Projector Performance
Depending on how you mount / position, the SP8602, it can be anywhere from bright to very bright among the competition. Certainly, at its worst, it's as bright, in best mode, as the JVC. From our own measurements: 785 lumens for the InFocus in "best" mode, at mid point zoom, lens at 0 offset. With the same settings (mid-point, 0), the RS15 clocked in at 657. In brightest mode, no contest - InFocus 1110 lumens vs. JVC's 746 lumens.
Further, if you have the ceiling height, and can mount the InFocus at its maximum lens offset, (for a 100" screen, the center of lens about 15" above the top of the screen, you pick up about an extra 18% more lumens. That translates to about 930 and almost 1300 lumens. And all that is with Brilliant Color off. Turn it on and you get about an additional 35%. But, InFocus'es Brilliant Color, while pretty good, is definitely not as natural looking as with it off (which they call "Normal" - vs. "High" being on).
In other words, the InFocus, is always the brighter projector, and if you bring every factor into play, in brightest mode, it can be a full 60% brighter than the JVC!
What about sharpness
No contest. I'm not convinced that the SP8602 is as razor sharp as the older IN83, in fact I'm pretty certain it's not. Still, it's a pretty sharp DLP, and that makes it sharper than any LCoS projector I've seen, except maybe an RS35 with perfect pixel alignment.
No question that the RS15 looks softer than the InFocus - it's not great at all, on movies, but on pure HD digital content, the InFocus adds that extra appearance of sharpness that I really find to be an improvement. I've always complained (slightly) that I wish my own JVC was a bit sharper, primarily for all that HDTV sports and digital Discovery-HD and similar content.