I suppose it’s about as “perfect”* as it can get since it does indeed support 480p (“YUV signal auto scan” in the manual), the only catches I see are, assuming you want to leave one cable hooked up and not switch/split the signal, does SCART RGB support 480p (I think it does?? Rosser, a little help?), and if not, are you OK with the slight drop in color quality if you have to use Component (I’m as much of a video nerd as it gets and I’d be OK with it :P)? Does the scaler output in your TV’s exact native resolution, and if not, does that matter? It doesn’t do 1280x720 (720p) but it does do close to the common 720p TV resolution of 1366x768 with its 1360x768 output (it should be 1366px wide… if your TV doesn’t do 1:1 pixlel mapping and it’s such a TV, then you will throw away some clarity). And it doesn’t do 1080p at all.
*Let’s not get into things like the Theoretical Best Scaler Ever that has hq2x filtering onboard (for those that hate pixels), 0f of lag, and has a HEPA air filter built in
or get into more expensive scalers like the XRGB series
Other than that, this scaler does have a little lag (they all do unless they line-double through entirely analog means or something, though some are less than a frame or something like that and are basically perfect, again I’ve never dealt with them directly so this is all me going off of random stuff I (think I) know). If you are really lucky and the GSModeSelector PS2 scaler program is perfect for you, it is lagless and would be an alternative solution (though it’s not a fun program to set up).
I do also agree that while you’re not 100% in over your head, you’re seeming like you’re about to jump head-first into something you don’t know much about (sorry, no offense). Perhaps do some reading to familiarize yourself with what you’re dealing with:
http://nfggames.com/games/ntsc/
http://nfggames.com/atarilabs/meat/2000/1201_rgbprimer.shtml (if you want, but the above covers most of this info)
http://gamesx.com/wiki/doku.php?id=av:av_mods
http://www.chrismcovell.com/gotRGB/index.html
http://en.wikipedia.org/wiki/NTSC
http://en.wikipedia.org/wiki/S-Video (optional)
http://en.wikipedia.org/wiki/Composite_video
http://en.wikipedia.org/wiki/Component_video
http://en.wikipedia.org/wiki/YCbCr
http://en.wikipedia.org/wiki/Progressive_scan
(etc… This is just to start you off…)
IMO if you were OK with S-video being your top quality input for some consoles, and your TV had an S-video input, and supported 240p, and had an acceptable amount of lag for SD sources, and produced an acceptable image from SD sources, you could save a lot of money and trouble…
edit: Thanks UD, this comes from years of being a video nerd… I learned basically everything from the Neo-Geo.com forums and the gamers there. Most of us over there know all this stuff lol.