If you share your login information with anyone for any reason at all, and they find out about it, they will disable your account.
We've had to rescue a couple of NFS.net users that have made a mess of things one way or another. Getting NFS.net users sorted out is a very-not-fun game of cat & mouse with NFS.net support. This isn't really a criticism of them though -- I like NFS.net overall -- just something that potential customers need to be aware of.
edit: went back through my email so that I could provide a more specific example. Owner of a small board game business had a website developed by his technical partner; technical partner hosted it with NFS.net and then became completely unavailable later on; website was then compromised and used for SEO spam (probably stolen FTP credentials / bruteforced lame password); business owner saw his website disappear altogether from Google listings with no idea of what was going on. He became our client at that point. While this was happening, his NFS.net-registered domain also expired, and the email address associated with his NFS.net account was at his domain (!). NFS.net support flatly refused to respond to any matters regarding his account from any email address other than the one at his expired domain, which couldn't be resolved until account access was restored, which was impossible as long as the domain was expired ...
Unfortunately, I don't have notes on how that particular one was resolved, but there are a bunch of domain transfer notifications shortly after -- I suspect we weren't able to ever resolve the trouble with NFS.net and resorted to something along the lines of transferring his domain, re-hosting it, and rebuilding his site from Wayback Machine archives or something. (He had no backups, of course.)
None of this is NFS.net's fault. There's a good argument in favor of the way they handle account access. On the other hand, with any other hosting provider, this could have been resolved far more easily. ("Tech guy set up my website and then disappeared" is unfortunately a common problem.)
Having ssh access and quite a bit of tech freedom, for either CGI stuff or just manually run command-line processing, is also quite nice. And although not everyone likes it, I like their idiosyncratic custom web admin panel.
Still the cheapest and my own site is there (I'm too busy with other things to move it), but no longer my favorite.