I just ordered 30 of these to replace most of the biners on my rack. I am hoping for the smaller size to cut down on bulk. I have done quite a bit of research and found nothing that suggest a smaller biner is a bad idea. Anyone have any other thoughts on using these biners for multi-pitch routes?

I agree with steph that once you get used to these biners, they are actually easier to clip than larger ones. They have beautiful, smooth gate action and because I have smaller hands they are actually easier to clip for me.

I've replaced all my biners with these, even sport draws! The weight is unbelievable. On a big rack of gear, you will immediately cut down half the weight. That means you carry less, weigh less, and climbing is instantly easier! Presto! Initially I thought smaller biners would be harder to clip (like on the sport draws), but now I am so used to them that I actually find it harder to clip big, heavier biners. I am totally in love with these things, and give them all thumbs up :)

The only problem with a smaller biner is that it's harder to clip the rope into on a desperate clip, so often people just replace the bolt side of their draws. On big alpine routes, that's not such an issue, so people replace all of them. If the fast clipping isn't an issue, then go for it.