The most amazing rhythm game ever! Period. Harmonix does it once again.
Having a very active online community has only helped them. When it comes to pleasing their fans/customers Harmonix is second to none. I know of no other developer that listens to their customers' wants and concerns so intently. All the improvements that I ever wished for have been addressed in this version of RB. Every aspect of the game is an improvement. If you're a previous player you're probably aware of the minor shortcomings of the previous games. IMO, all of this has been fixed.
As far as talking about actual game play, I'll focus mainly on pro mode:
Pro mode for keyboard is amazingly fun and I look forward to improving my skills (they definitely need it). I play predominately expert guitar but even playing pro keys on the easier difficulties can be rough. It's a lot easier to know what buttons to press when there is only 5 (on the guitar) versus 25 (with the keyboard)! You can't really cheat by looking at your hands because then you'll miss notes on the screen. Regardless, I look forward to this challenge and know it will be immensely entertaining and fulfilling.
Pro mode for drums is great fun as well. Finally we get separate notes for the cymbals I've had for nearly two years.
Of course the guitar/bass Pro mode is the star of the show, but not many average Joes such as myself can say much about it yet. The Fender Mustang controller is still about three weeks away from release, and the real Fender Strat controller is even further off. I've watched every video and read every review in relation to these two peripherals and came to these conclusions:
1. With any game controller/instrument this sophisticated, perfection for every possible user is impossible. It's also not going to be cheap.
2. If you want to actually learn to play guitar, Pro mode is your best option outside of buying a guitar and plunking down money for lessons.
To address GameSpot's other negative concern as for the price of the keyboard... For one, it's an actual instrument. It has a MIDI jack, and with software (which you can get for free) and a cable, you can start creating those concertos on your computer that have been mulling around in your head. Also it is very solid and feels very well made.
In closing, I would say "read the reviews!" Go visit Metacritic, Amazon, GameRankings, etc. I have never seen a game in this genre with such positive reviews. It's rare for any genre. You don't want to pass this up. If you're a follower of the genre, it's the absolute best there ever has been. If you've been on the sidelines, there is no better time to get into the game.