The only feature I miss with your CardDAV implementation is contact photos. Everything else works very well so I leave email and calendaring to FastMail but I'm back to self-hosted contacts for now. Really hope this can be added soon.
Interesting, I'll have to try again. When I first used the beta I imported a VCF exported from ownCloud (which I think stored the images as data URIs). I'll try to figure out how to upload them via CardDAV now, thanks.
To add something to what @robn already said - with Google Apps the resolution you get on contacts syncing is 96x96 pixels. Not sure what resolution FastMail supports, but seems to be OK on my 1440x2560 phone.
