Personally, I like using the Roomba. It's not great, either, but I don't mind picking up the room and letting it run.
I'm sure there's a large market for traditional vacuums, those always seem to get most recommended. Miele canisters are always considered "the best," but reviewers know most people aren't interested just because of the price.
There is a huge range of corded vacuums that should not exist. I'd say this line is marketing crap. Even V10 isn't corded replacement across all corded vacuums.
> I need to clean things, I think I'm the target audience!
It all depends on your use case. If all you have is hard floor and a studio sized apartment, you don't even need a vacuum cleaner. Same way not every one needs a Ferrari to get from point A to B. Dyson's price range is certainly a good indicator as to why it's for a smaller market than your average vacuum cleaner.
I need to clean things, I think I'm the target audience!
Maybe from what you say then the V10 could swing me (certainly sounds like it has the issues that annoy me sorted out), but that's what was said about the V6 - corded replacement, easy empty, long running time, etc!