0-60mph in 5.0-5.5 seconds is really pretty damn fast. It’s in the same ballpark as, say, a Subaru WRX STI or an Audi S4. The lightness of the bike makes it very nimble and easy to flick from side to side, and I can still smoke 99% of cars on freeway on-ramps (not that I do…mind you…*ahem*). Best of all when you’re beginning, you can really muscle it around at slow speeds to avoid what would be drops with a heavier bike. The price, fuel economy, and insurance are all other selling points. Top end is also not your concern at this point. Just about any motorcycle will go faster than you should on the street (though I’m all for whippin’ it up at the track). The 250R doesn’t have any problem going fast if it needs to (e.g. freeway haul at 70mph), but it does rev high to do that. Some people get unnerved running the engine at that level and feel a bit more vibration than on other bikes. Honestly I never found it to be an issue.
Second, NO CBRs! No R6s, no GSX-Rs, no ZX-6Rs, no Daytonas, no race-tuned bikes! These are NOT beginner friendly bikes at all. The difference between these and a 250R is night and day, and will probably not make you the better man for it. There are lots of great beginner bikes suggested all around this site, so really scrape it for everything it’s got.
Finally, just so that you don’t think this advice is coming from somebody who doesn’t like to go fast and have fun, I do own a bigger and faster bike now, and I visit the track pretty regularly during riding season. All the same, the 250R still sits in my garage because it’s the better of my bikes for commuting and riding around town.