planning to buy either one.. anyone owns/know which one is more worthy to buy?

I just only saw this...

depends on ur preference actually, RB seem caters to more popular songs while GH tends to be more on rock/metal kind of songs...

also it depends if ull be playing alone or with a group of ppl.. RB experience in a group is better compared to GH but if u gonna be playing alone, seems that GH solo mode is a better choice...

actually if u can just go for both, the guitar controller for RB works for GH and vice versa... so just get one of them with the guitar/drum/mic set, then just get game only for the other...

like me i have Rock Band 1, The Beatles RB and also Guitar Hero 5 games, but my controllers all rojak, RB2, GH5 and GH3 guitar + RB1 drum kit and mic...lol

for me... i prefer rockband. solid construction and tougher foot-pedal. i bought additional triple cymbals set and it does feel like you're bangin a real drum set, and i found RB songs are more fun to play compare to GHWT or GH series. but then if you like metallica, you should buy GH, RB doesn't have that in their list. only on RB1.

i saw GH can custom your own song but RB dont know can custom or not.

is it true the hw is interchangeable for the games? meaning to say if i were to buy a RB hw, i can still play GH games?

yupe... RB controller can work with GH game and vise versa...

http://www.joystiq.com/Instrument-Compatibility-Matrix