I had one of the first great Android phones (HTC Droid Incredible) and kept it until about a month ago when I bought a 4S. Is Android a quality phone OS, absolutely. Are the new Android phones superior to the 4S in terms of hardware, yes again.
The kicker is this, I bought the 4S because it was the right phone for me right now. It has a great form factor (I prefer a smaller phone.. again, preference), it is reasonably fast in 3G, and it's reliable as hell. It doesn't do more for me than my old Android phone did (except for the customization part, but I didn't root my old phone anyway), but it does exactly what I need it to do and more.
In a couple of years, who knows?? Just imagine what we'll have available in two years.
The Droid Incredible was one heck of a device and it was fast, too. I wish the build quality was better in regard to its plastic housing unit.