Do you notice brake shuddering in the front under hard braking?
No, but not enough miles to be definitive. It's something I'm watching for as I've heard this about the Poprad and wondered if it was the fork causing it. I always got the impression that it tended to be on the rim-brake version though.
The forks on the 08 Poprad non-disc look like they'd be a lot more rugged and stiffer.
I've confirmed this to be so, as I test rode both. But the 08 canti version has TERRIBLE fork shuddering and it was really much more pronounced than it was in the disc version.
Again, I suspect the wheels, which are poor.
I took a long ride yesterday and did some hard braking. No shudder or other brake problems. So this would support your theory that the problem is with the wheels.
Having said this, I'm not terribly impressed with these Shimano R505 brakes - lever pressures are higher than I think is optimal and they feel a little wooden. I think I'm spoiled by the BB7's I have on my Giant mountain bike which have a very light touch and superb feel. (Maybe too light - the first thing a friend of mine did on my Giant during a test ride was loop the bike on a tight downhill trail.)
After a couple hundred miles, some further impressions which might be of interest to folks thinking of building up a new CX bike....
1. The Everti butted/shaped 3-2.5 Ti really does a very nice job in the ride/stiffness compromise. The ride at the rear is especially forgiving. No feeling of whippiness or BB flex either. This would make a superb touring bike. Handling is neutral and nice. Everti advertises the Odyssey as their do-everything frame and this is an accurate representation.
2. The SRAM brifters, RD, and cluster work great. I really like the shape and action of the SRAM brifters and the shfiting is strictly snick-snick. Double-tap (misnamed IMHO) is a neat system and you adapt to it almost instantly.
3. Love the 34-50/11-28 gearing. I just leave it on the big chainring 95% of the time and treat is as a single-lever 10-speed. (I can use the entire rear cluster w/o having to trim the FD which is a good thing as SRAM provdies no trim on the big chain ring.)
4. The Ultegra SL compact crank is very rigid and looks great in the gray finish.
5. Didn't think I'd like Fizik Arione saddle, but it's a winner.
6. The SRAM 10-speed chain Powerloc connector gizmo really is pretty neat in how it works.
7. The Bontrager carbon fork is not terribly rigid, but is rides nice and I'm not getting any brake shudder.
The Bad (not much):
1. I really had to fine-tune the Rival FD to get it to work well. There is a +/- 1/8 turn fine adjustment of high gear screw that allows you to reliably shift to the big chain-ring without rub or overshifting. It's fine now, but I spent an easy two-hours messing with it. I was originally going to try a Ultegra FD, but got worried that it might not like the cable pull spec and lack of big chainring trim of the Rival brifters. If I did it again, I'd try the Ultegra FD.
2. The Shimano R505 disc brakes are noisy and have a metallic grinding feel to them. Don't work that great either. I think Shimano specs metallic pads for the front - I may look into different pads. Still feel like BB7's are a better disc brake.
3. SRAM says their Rival RD has the capacity to handle the 11-28/34-50, but its marginal at best. Using the standard big-big+2 chain sizing protocol, I can't use the smallest two gears in the rear cluster on the small front ring without the RD cage going limp. I may try removing a couple links, but the chain may be too tight in the big-big combo. I just don't think the Rival RD has the required 33T capacity.
4. Cost: Don't build a custom bike thinking you're going to save any money, at least not unless you have a bunch of free parts lying around. A Poprad (or any consumer bike) basically sells for the money you'd spend buying all the components - the frame goes for free.
I'm going to be putting a ton of miles on this bike.