In reply to ArnoldTheBat:
Personally, I really like the Katana laces. I also have a pair of Instincts that I boulder indoors in.
With the Katanas I go down from 45 to 42.5 and find them very comfy, e.g. enough to do 10 pitches of delicate slab in 27°C heat. They have a tough break in period though (miserably shuffling around the house a few times; a couple of indoor sessions where they feel awful and insensitive). Then they're incredibly good!
Alternatively, I have a pair of blue UP Lace that I find ok. Personally, I often find them too soft, but they are comfy. The LV version has a shite heel in my view, but perhaps I'm in a minority on that.
Finally, I love the Vapour S downsized as a bouldering shoe. Much better than the lace version, which I really don't get on with. Might be good as a trad shoe if not too downsized.
Hope one of those works!
Post edited at 21:49