`curl ... | sh` installations don't really bother me. The scripts tend to be short and commented, or at least readable. Sure beats running an opaque .pkg installer, which invariably asks for your password (presumably for no reason) and installs god-knows-what all over your hard drive.
Yes, but if you're doing curl ... | sh then you're not vetting the script you're running before you run it. If you were, you'd be running curl and sh as separate commands.