I spend a decent amount of money on domains every year. I think I own or take care of maybe 100 domains.

I use EnomCentral because I have a reseller account with them through hostgator (~10$ per domain) but they have grown more and more into an upselling machine. They automatically assume you want a free trial of their Content Writing program. I uncheck it everytime. This is annoying.

I've lately been buying all of my domains through NameCheap. They offer a free SSL cert and free privacy. They don't do much upselling, as I recall. If they do, it didn't bother me as much as Enomcentral.

I don't think upselling is a bad thing. I think it can be a good thing if I see value in the product they are upselling. If not, that's when it's a bad thing. Automatically adding a free trial (w/ a monthly fee after the trial) to my cart when it's something I don't want is horrible.