Cyclocross - New to CX & 2007 Felt F1X

Now that the end of my first season as a roadie is fast approaching, I find myself needing a cyclocross bike for racing/training through the fall & winter. I've been looking for a used one on Craigslist for months, but never can find a good one in my size. At first I was thinking of going the cheap route and buying the Motobecane Fantom Cross for about $700, but I was having the chain replaced on my Felt F2C and I saw 2 bikes I'd much rather have. 1st was the steel Lemond Poprad. Very nice looking bike for $1099, but maybe a bit heavy for racing. I had been looking at the 2006 Felt F1X, but at $1,449 it was a little more than I wanted to spend, but today they had just one 2007 Felt F1X, and it was in my size (I think - 53cm). Anyway, the guy at the shop said that they've been re-specked for 2007 and will be less expensive. He didn't have a price (they just got it and built it today), but thought it would be around $1,200.

I haven't been able to find detailed specs for the 2007 model (anyone?), but here are the differences I could see from the 2006 model:

Frame is the same as 2006.
2006 has 10 speed Ultegra shifters & derailleurs, 2007 has 10 speed 105 shifters & front derailleur, Ultegra rear derailleur.
2006 had 48/39 chainrings, 2007 has a compact 46/36 double.
Sorry that's all I was able to notice before I had to go, but I plan to go back soon for a test ride.

My first question is, what should I look for in a cross frame's geometry?
I know that the chain stay length and wheel base are a bit longer than regular road racers, and it seems that the bars are usually higher (stems usually flipped up for CX and down for road racing?)
I ride a 54cm F2C road bike and was thinking that a 53cm F1X should be the right fit. This LBS is pretty good at fitting, so I'll have them fit me on it to see.

Any opinions on if the F1X (even with a 105/Ultegra mix) is a good bike for racing?

Thanks in advance.

I have a pair of F1X's, a 2005 w/105 and DA, and a 2006 full Ultegra. I have raced and trained on these bikes for a year and I dont have any complaints, other than some parts that i dont like -- but that's personal preference. I race CX in the northeast and see alot of them at the races. Plus, if the frame is good enough for mark mccormack and jesse anthony, its good enough for me. Check out jesse anthony's rig here:

http://www.cyclocrossworld.com/BOSS.cfm?Action=Edit&theKey=8&ShowDisabled=0

I'd say the F1X is better than "good" for racing -- its great. nice and light and very nimble. Mine came with mavic cxp-22's wheels which are bomber, but quite heavy. this year i'm going tubular. surprisingly, i really love the stock saddle. i hate the tektro top levers and i'm not that happy with the brakes either -- stopping power is good, but mud clearance is not good. i have no problems with the fork -- no chatter at all and its light and stiff. btw, my bikes are 50 cm.

there's lots of good cx bikes out there and its hard to go wrong, esp if its your first year. if you buy a complete bike in the 900-1500 range you will get a good machine, but the spec will cut corners somewhere, thats just the way it is. if i were you id make the decision based on fit and feel, because you will inevitably break/swap/upgrade components over time...

Find out what the TT of the road bike and see how it compares to the cross TT. The rule of thumb is to get a frame that's a little shorter in the TT. The Giant that I race comes in about 0.4 cm shorter and it works fine. Also, remember that the standover height of a std cross bike will be a little taller than a road bike since the bottom bracket drop is less for a cross bike. As for the cranks, I would go with the one with the smaller rings but it depends on your fitness. As for the derailleurs and shifters, go with the cheaper ones since cross is pretty hard on 'em...you can always replace 'em.
On my stuff, I went old school, meaning that I use bar ends for shifting and std brake levers so if I biff it and bent a lever, the shifters wouldn't be affected.
There's a old saying that someone told me, "if you ain't crashin', you ain't going hard enough!"

i just bought an 06 lemond poprad and went through the same debate to go with it or the felt....if i had known the '07 felt came with compact cranks i would have held out and bought that and put the 10 speed ultegra on my road bike and put my aging ultegra 9 on the cross bike since (as dlbcx points out, and what everyone has warned me) you crash more often in cross and pricey components are pricey to fix. depending on what you have now on your road bike that might be an applicable option for you?

I have an '04 F1X and it's become my favorite ride. It looks great, is very strong and reliable, and most importantly fits me like an old pair of jeans.

Although I've replaced a few parts (Salsa bars, FSA Gossamer crankset 36/46, WTB Stealth saddle, Felt carbon post - I don't CX race, IRC Mythos 32 CX tires, ESI grips, SRAM 11-26 cassette) the most important swap I did was get a stiffer stem. The OEM Felt OS stem is VERY flexy when you're hammering out of the saddle. I'm running a Thomson Elite X4 (MTB) stem and flex is all but gone.