Well, for me the catch is that I don't want a band recording in 2009 to try and just copycat something that was recorded in 1983. It's fine to try and capture some aspect of 80s metal, but the 80s are over, and we've had countless bands since try to just ape the sound, look, style, cover art, lyrics, etc etc. 99% of the time I'm not really interested in listening to a new band try and pass themselves off as a Manila Road cover band (not picking on MR, insert any 80s Metal band name and the statement remains true). They never sound as good, so if I want to hear Manilla Road, I'll just listen to Manilla Road, rather than Manilla Road 2.0
Perfect example: Ironsword versus The Gates of Slumber. I've heard one album from each. Ironsword just try to look and sound like Manilla Road. Yawn. I found their album boring and downright cheesy. TGoS have some clear influences like MR and Cirith Ungol, and at times they sound like them, but overall they use their influences to create their own sound. It may not be an entirely original sound, but it's a much more interesting approach than just copycatting a band that existed 20 years ago.
That's my take on it.
"I'm sorry Sam, we had real chemistry. But like a monkey on the sun, our love was too hot to live"