In reply to Tigger:
Hi there, quite a lot to go at here. I always have lots of pairs of shoes which I've settled on through empirical testing rather than the glossy bobbins from manufacturers.
So, always XS Edge unless there's a very good reason (Sportiva Testarossas are XS grip but fit my feet better than anything else, so they get worn out and resoled in Edge).
Scrap Instinct Velcro newish for hard stuff; old, worn in, comfy and resoled for punter UK bouldering, Font Circuits and holiday bolt clipping. Instinct Laces for projects and anything that doesn't require wearing them a lot (can't walk in them).
Scarpa Stix for slabby grit, these get resoled in Edge for bouldering eventually.
Trash pair for 4x4s and circuits at the wall.
When I used to climb trad, one pair of EBs got me up most stuff, however my usual top grade was English 6a and occasional 6b if I got lucky, which means that now I boulder virtually exclusively, I need all the help I can get!
Mrs P_in_S swears by 5.10 Stealth rubber, but I hate the shoes so I'm going to experiment resoling an old pair of Stix in it to see how it goes.
So there you go, shoes to do different jobs from 1 day to 1 minute and in different places. I've found a rubber that works for me purely through use.
btw, Mrs P supervised an Engineering Design Masters project which analysed the differences between Edge and Grip ( experimental rig, different rock surfaces, force plates, strain gauges etc.) The outcome identified 65kg as the lowest useful body weight for Edge, any lower and Grip performs better across the board. There is also a temperature effect which moves this around. Interestingly, not the rock temperature but the temp of the foot. So if you've naturally cold feet in grit season, the body weight to switch to grip is higher than 65kg. This research hasn't been published, but I think I've got the main facts right.
Paul