In reply to J1234:
Where your foot is broad is an important thing to consider also.
My feet are quite wide (due in part to a lot of long-distance hiking) but not just in the toe-box.
I find that with Sportivas (even those supposed to be for broader feet), I get an unpleasant ache level with the arch of my foot after about 30 mins of wearing them. The only pair I've found that I can wear for longer periods of time are Solutions.
5:10s and Tenayas are way too narrow for me.
Scarpas are generally comfortable.
The classic advice is to try them on in a shop but I'd go one further and say to look out for boot demos at your local indoor walls (if you live in a city?). You can only tell so much about the fit of a shoe when it's brand-new and you get to pop it on for 5 mins and stand on an artificial pile of rocks in a store. Have a go of all available pairs of already worn-in shoes and get to try them out on an actual climbing wall over a session. That's how I found out that 90% of sportivas are not for me.