Here's another second--third?--to the fact that a 430W is really the minimum GPS box for serious flying. And I'm biting that bullet this coming week with the installation of a new 430W and GPSS. The GPS steering is pretty inexpensive, as things go in the airplane business, at around $1500, and with that addition, you really have the ability to fly comfortably with backup in most weather. The installation cost for the GPSS is minimal when done with the GPS, and once it is done, that's it. The stuff I read shows more and more GPS approaches with vertical guidance being published at smaller airports and that the trend may well be for the ILS to go away slowly in favor of those new approaches. They cost nothing to maintain, and my experience shows the glideslopes to be much smoother than those of many ILSs.
I went around and around about the 430 vs another box, and the Garmin ended up being the most cost effective. I found one (430W) with only 10 hours on it in Shenandoh, VA, that I almost bought ($8995 installed) but couldn't spend the time to have it done. I don't know if that one is still available, but if you're interested, post an e-mail, and I'll put you in touch with the installer.
The other candidate was the 530, but I thought it too big for the panel where I wanted to put it. I'd still love to have one and an MFD.