There's a few of us on here that have corgis. Some have pemmies, some have cardis. I have pemmies. My opinion? They're the best breed EVAR.
You worry about doxie spine issues. That is also a worry with corgis, although it's my understanding that it's more of an issue in doxies than in corgis.
As for what they're like? There's a pretty wide range. Many pemmies are working/sport quality and therefore are fairly high energy and high drive. They're an extremely intelligent breed. They learn fast, but often learn bad things.
They're very clever and mischievous. Absolute clowns. There's never a dull moment with a corgi around. Don't underestimate their short legs either. They can and do get on tables and counters.
Dog aggression and resource guarding aren't at all uncommon in the breed and some corgis can be quite scrappy about that. I suspect there's common ancestry with terriers somewhere.
Some corgis are very vocal, others not so much. Be prepared for a barker and if you don't get one that barks a lot, be grateful. Pemmies are very outgoing with strangers.
The coat is a short double coat and there's usually a lot of seasonal shedding. Exercise requirements are medium to high. They typically do have a good off switch as long as they are kept sufficiently stimulated - mentally even more important then physically. Most have a very high food drive.
And if you do get a corgi, pictures are required.