The only downside is the email hosting. I was used to free email hosting from Gandi so it's annoying having to pay now - $10/year/mailbox.
Huge advantage of Hover: if you have domains elsewhere, you can give them your credentials for the old registrar and they'll log in and transfer your domains over (and DNS, etc). Saves a bunch of time.
Finally, if you don't go with Hover, go with Gandi. Their interface isn't nearly as nice but the support is good and they won't screw you around.
It really pays to make sure you have a good registrar.
ICANN rules require registrars to support DNSSEC for clients, but hover use their "reseller wholly owned by the registrar" status to avoid consequences for not implementing support for DNSSEC.
To add insult to injury, they claim they "support" DNSSEC because you can submit a support ticket for them to manually upload the required data, at a cost of $500 per time per domain.
They responded to customer queries about DNSSEC support for four years with "yes it's coming soon". It was only when someone filed an ICANN complaint that they admitted they are not and were never working on support, and have no plans to.
They specifically market themselves as "no upswell, no hassle" - so yes I think their behaviour warrants being called scumbags and any number of other less polite names too.
They're fine, nothing special—but that's what you want, right? I register domains there, and the name-servers automatically get set to my defaults, so I don't interact with them much.
Importantly, they aren't obnoxious about up-selling, they send 2-3 email notifications before a domain expires (1 month out, then again in the days before expiry), and you can mark individual domains as auto-renew or not.