I know the conditions well as I live in Ottawa myself. I tried a few skis in your range at Calabogie (T&L) a few weeks ago. At 200 lbs, 5'11" sking on mostly machine groomed (ice in the pm), I am having difficulty deciding on a replacement for my 2003 Volkl Allstar.
I tried Dynastar Contact 4X4 in a 170 and I found it too flexible and I felt that it didn't even come close to holding an edge like my present skis.
I also tried three skis from the Volkl AC family with the following results:
AC20 - 170 - Similar to the 4X4 but a bit more edge hold. Fun but can't see myself having much fun with them on steeps at Tremblant.
AC30 - 177 (I think) - Loved them, the responded beautifully to everything I asked of them.
AC50 - 170 - Beautiful in a Cadillac sort of way ... problem was I didn't want to turn ... Too dangerous for me I suspect !
Nordica - Hot Rod - Top Fuel - 170 - These things were truly amazing but stiffer than the Volkl thus maybe to much ski for me as I'm approaching 50. They did however make me want explore more skis out of the Nordica line-up.
I guess what I'm trying to say is I tested these all on the same day. It was loads of fun and I learned a few things. I'm not even close to deciding on anything yet, however ya have to get out and try the stuff out. Just for the record, two store clerks at different Ottawa stores strongly suggested the AC 20's. After testing, I'm sure glad I didn't pull the plug early ... I would have been disappointed.
Not telling you what to do ... just take your time and get it right.
Skis in this town are way too expensive to be making choices based on the experiences of others.