I put Pilot 6.9s on mine, like them a LOT. I had Simmons Gen2s last year, and when it was bottomless, they were great - otherwise, they really hindered sidehilling.
Rock hard or "once a year" deep, the G2s were great. Otherwise, ehhh.
The 6.9s, off an 05ish Rev, bolted right on, are WAY lighter than the Simmons, and I like them. Darting is back - the Simmons did not dart around at all, as previously noted.
I like the 6.9s pretty much all the time. I did not like the G2s MOST of the time, but the few days it was REALLY deep last season, the sled sat noticeably higher in the snow - a few inches. Makes sense, they're freaking sheets of plywood compared to anything else.
I suspect that the normal Simmons are great, and I'd not be surprised if the G3s are a happy medium, but IMHO, something with a center carbide (or just a single carbide) helps make the sled easier to roll on edge; I'd like to try Powder Pros, but I got the Pilots cheap at a swapmeet - and I have zero regrets. I put them on backwards initially, the sled was TOO tippy. Put them on "correctly" (some people like the wing on the outside - the Pilots are asymmetrical, one side has a "wing," the other side has a spot for a second runner; stock, the "wing" goes inside), the sled is really very well behaved. Almost makes me think Powder Pros would make the sled too tippy, also. Dunno. I'm done messing with skis - I hated the stock ZX skis, darty, weird feeling, ehh. The Gen2s were just too big most of the time. The 6.9s are cheap, light, and I have zero complaints, beyond darting (but I suspect the darting has more to do with single-carbide and the fact that mine are WORN badly). I can live with the darting, it only does it on groomers, and groomers are stupid
.
If I need to replace these skis, I'll put another set of Pilots on - there may be better, but these really do the trick for me; easy to sidehill/get an edge, decent float, shrug, no complaints.