I don't think it would be a bad beginner bike. It's a little heavy, and it a pretty good hit of low-end power, but it's a pretty manageable motorcycle. They look really cool too. Dealers are discounting Harleys under MSRP in a lot of places to get rid of bikes that aren't moving. It would be hard to think of a better time to buy a new Harley.
My only complaint about the Nightster is the lowered rear suspension. I wish they had a standard and a low like the old Sportster had. I loved my '05 1200 and I wish I had never sold it.
Go to the dealer for the "Riders Edge" course, and tell them you want to test ride one as soon as you have your license. Even though I am betting you will like the bike, it's never a good idea to lay down cash for a motorcycle you haven't ridden. See if they have one in the rental fleet, and pay for a weekend. Then you would be sure.
Lots of people rip on HD, and even though they are slow compared to a lot of bikes, and a little overpriced, they are still great machines. Plus, if you into the group ride scene and hanging around with a big group of riders, it's hard to beat the HD experience.
I don't hold loyalty to any particular brand. I have owned them all, but I liked the Sportsters I have owned.
Ever consider a Buell? I love my old Cyclone. It's all the things I liked about my Sportster, but with a lot more power, better brakes and suspension, and a larger tank. It isn't a great starter bike, but maybe in the future you can give the brand a shot.
Good luck.
