I'm on the market for a new bike. Something raceable, but I do a lot of climbing, so I'll be going with compact cranks, which is what I had on my previous primary bike. Old bikes had older 9-speed Ultegra, with non-Shimano cranksets. I'm not a master of bike adjustment, but I did a fair bit of tinkering with the shifting (especially front shifting), but was usually not able to completely resolve chain rub issues - which I think may have been due to some flex in the cranks, since the rub only occurs during part of the pedal stroke.

So now I'm looking at some new bike options, most of which feature Ultegra shifting components, but proprietary/third-party cranksets. For example, Fuji's Altamira 2.0 uses Fuji's own Oval brand, while various levels of the Specialized Tarmac use either FSA Gossamer Pro or FSA SL-K light. I'm not a weight weenie - slight differences in weight aren't much of a selling point for me. But I do value smooth shifting and noise-free riding. How much performance difference should I expect between these cranksets, and the ones that are actually part of the Shimano gruppos? What's the best way to evaluate this performance on test rides?

To figure out why those cranks are on those bikes, you have to follow the money. It has nothing to do with weight or shifting performance. Shimano cranks are much more expensive and thus are not spec'd onto the bikes.

My experience with Shimano vs. FSA -- Shimano is leagues better than FSA in front shifting performance. Especially 6700. Shifts are immediate, consistent, and smooth. FSA -- not so much.

I've heard good things about the shifting with PraxisWorks rings. If you find the stock rings aren't to your satisfaction you can try that route rather than completely swapping out the crankset.

I can't comment on Oval.

I agree that Shimano shifts better than FSA, but I don't know if I would have said leagues better.

The crankset is one of the top places you can save weight, but if that doesn't matter to you then you can ignore it.

Since you say noise-free riding is a priority, you should look closely at the bottom bracket standard being used. Like you, I value noise-free riding and so I was very happy to find a nice frame with a BSA threaded bottom bracket. I've heard a BB30 creaking, and it scared me away from those for life. Supposedly, the PF30 (sometimes referred to as PressFit BB30) solves that to some extent, but I still prefer threads. (Of course, I am aware that the threads on my carbon frame are pressed/glued in place, and so I might be deluding myself somewhat.) You hear that BB30 is about stiffness, but I'm of the opinion that the biggest thing it gives you is weight savings. I also read somewhere that it saves on manufacturing costs.

Probably the cranks in question did not run quite true. None are perfect, some are better than others. Shimano cranks are good, I have a pair of VO cranks that are particularly poor in this regard. My FSA cranks are actually pretty good for this.

It's easy enough to see, just look down while riding. To test the shifting quality of the rings, shift the front up and down under load.

If the bottom bracket is using a BB30 design you won't find shimano cranks as they don't have a BB30 fitment (but they do for MTB so go figure...). I know my friends Giant uses Shimano cranks due to the BB86 design. I've second that I've heard that 6700/6750 (compact) cranks shift the best.

Hope this helps.

Just to keep from any potential shifting problems like I endured on my Trek, when I bought my Specialized Secteur I paid an additional $150 & had a Shimano 105 crankset put on my bike before I ever rode it.
Was it worth it? Well I haven't had any shifting problems & it's nice & smooth.
Maybe it was more for my piece of mind but I hate having to constantly mess with some component when I should be riding!
If you have more experience than me just test ride bikes with both cranksets on them & then decide.