I like it. I would put the spinning ATARI logo on there. I think that would just top it off.
I did try that but it didn't look quite right. I don't think Atari used to use the logo much in sideart.
Or, try off-setting the centerpoint of the lines... move them up a bit. Might be worse, dunno.
Thanks, I'll give it a try.
Another idea is to add some "perspective" lines to the text.
That would give it some depth.
I thought of that but I am not sure how to do it. ATM the lines are actually rectangles...I suppose I would need to make them into triangles to achieve this - I'll see if I can do it.
try making the text black with a white border or vice versa, make it stand out more
just my 2p's worth 
It does make it stand out more but somehow I don't like it as much...maybe because you don't often see the Atari logo/text with a border, I don't know.
Varying the thickness between colors may add what's missing.
Also, don't know if you want to change the colors a little to have it tie in more to the rest of your cab. At first glance, the art doesn't seem appear to me to tie in together, not that all of System1s sideart did.
Good idea on the thickness

I've tried to use at least some of the same colours throughout, but you're right. I don't mind the control panels not matching the rest as I am going for almost game-specific styles for different CP's (eg my Pole Position-esque one). Maybe I should try to match up the sideart & marquee more...yesterday I tried to incorporate the System1 logo in the sideart, but wasn't happy with it. I'll play around some more, maybe try out the sideart pattern in the marquee.
I like it, but I would make the black sections a very dark blue instead.
I'm a little wary of dark blues, since it seems hard to actually get one in CMYK - I tried it with a purpley-blue though and it looks pretty good

Maybe you could add some after-blur type lines to give the indication that it 'is' spinning towards you, as you suggested?
I gave it a go, but it seems to take away from the 'old-skool-ness' somewhat.
Thanks for all the replies, I have a lot of things to try out now!
