I have only had them on plastic so far. To hot to climb outside in Oklahoma. I am ready to get them on Oklahoma Granite.

Five Ten says that they should stretch out 1/4 size through use.

So far at the silo gym that I climb at (Rocktown in Oklahoma City) all of their natural pockets that are hammered out of the concrete. The shoes hold them well. I haven't got the best smearing performance so far, but we will see what a full break-in brings.

The Stealth Onyxx Rubber feels a lot firmer than the Stealth C-4 rubber.

I also own the 5.10 Spires.
My spire's are an 11 and are comfortable for all day wear. I purchased size 11 Anasazi VCS They are considerably tighter in the toe-box and can only go 1-2 climbs with out taking them off.

Overall they are an excellent second shoe to have when more performance is needed.

These shoes seem equally at home on plastic or rock. They are an intermediate shoe that is great for all sorts of little projects. They stretch a fairly well. (I have lop-sided wide feet My left needs .5 size bigger but I sized for my right. They have stretched to accomodate both feet now and feel like foot gloves)

I have climbed pockets, jugs, hand cracks (not good in tiny cracks), moderate bouldering overhangs, vertical, slabs, and just about any other terrain and they perform exceptionally well.

However As your climbing improves you will want to buy another pair of shoes that make the more technical routes less difficult. I am at that point now. Going to buy a new pair and send my spires to get resoled.( I am going to get them resoled with Onyxx Rubber)

Great Shoes for all around comfort and performance necessary for climbing arsenal.

Pros: Has a lot of room 38L. I can fit a 60 m rope, 2 harnesses, 18 Quickdraws, 15 loose biners, lots of (webbing, slings, and Cords), Some trad pro, 5 Liters of water (3L Camelback + 2 2L jugs, and extra stuff.
Roughly about 45lbs of gear and water and it feels very comfortable.
The mesh on the pack is very durable have hauled it up rough granite faces and barely and signs of wear and tear.

Cons: the pack lid isn't adjustable so it seems as though you loose some space and the ventilation is not that great still sweat a lot. (However what can you expect 45 Lbs and 100 degree heat.)

Great pack with a lot of purposes.