It really depends on the pitch in question. If there are a couple of <5.10 moves, then I can simply climb those in my aid shoes (Camp 4's currently). If the pitch starts with an appreciable amount of free climbing, then I'll leave the belay in climbing shoes and haul up my aid shoes (and rack) when the going gets tough. If there are a bunch of free moves at the end of a pitch, then I'll carry my climbing shoes and put them on when I need to, and leave the aid shoes (and rack) behind. (Slabby top-outs come to mind.)

One of the challenges with switching between aid and free climbing is that it's not just the shoes, it's the aiders, daisies, and massive rack required for aid. If there is a significant amount of difficult free climbing, all that crap weighs you down and gets in your way. Simply switching shoes doesn't always get it done.

I like to aid lead in my mythos (even for really long pitches) because they fit sort of like slippers and are comfy -- ultimately, I like being able to step out my aiders and free a move or two if that'll speed things along. Also, the approach shoes from La Sportiva (can't remember the exact name...) are pretty good for the same thing.

Are you starting Scott aid climbing this early?

Wahoo!!! You guys will have a GREAT time!

I found that until you start to get a rhythm for aiding, everything will just feel awkward. You might try starting out in some shoes that you "know" (i.e. your Aces?) and then if you decide that they're unbearable, maybe switch out to something else?

If you're looking for any suggestions for good "starter aid" routes, my first "aid" route was an hour ascent of "Chutes and Ladders" at Pinnacle Peak. Also, Sullie's would be a good option this time of year. You can set up the route and then aid the route on TR if you want to get the hang of what aiding feels like or the routes are so short, that you can just aid up 'em. When the snow melts, Paradise Forks (Davidson Wall) is great for practicing leading, hauling, and jugging. Also, the "sport rappelers" rock at Camelback is great for overhung jugging.

Enjoy!

Thanks for the great suggestions Lydia! I'm getting excited about aiding (I know, we're nuts)! Already looking for ascenders, etriers, etc. By the way, I don't think we're gonna make it out to Homestead....I've been fighting a cold the last few days and don't seem to be getting better.