I've owned a 1981 172RG for 27 years and well over 4,000 hours. I use it for almost all family, personal, and business travel over 75 miles. I used to be based at DCA, but am now at VKX. I have several comments on both the aircraft and the points raised in previous posts in this thread.
1 Speed. The certificated cruise of the 172RG is 140 knots and that of the current 172R is 124 knots. In my experience with both aircraft, these figures are accurate.
2 Range. The combination of cruise speed and 62 gallon tanks (six hours at 10 gph) are the strong points of the aircraft. In nearly all wind and weather combinations, I get an IFR range of at least 500 nmi. Here on the east coast, it is common to have large regions of low IFR conditions. With many other aircraft, I would have to scrub many short flights of 250 nmi or so, simply because there are no reachable alternates. I've made many trips to the West Coast and back, typically with four fuel stops out and three back.
3 Payload. I can fill the tanks and carry my family of three and a week's luggage. That's Washington, DC to Oklahoma with one stop; South Florida in one stop.
4 Operating costs. About the same as a standard 172. There's a retraction test at annual time but better fuel economy make up for it. Almost all parts are common with the 172 and therefore cheap and plentiful. Dispatch reliability is very good -- I've only cancelled a few flights in 27 years due to mechanical issues.
5 Operational flexibility. The landing gear can be lowered at up to 140 knots and is a great speed brake. ATC wants an expedited descent in a congested terminal -- lower the gear, throttle back slightly, and come down at an easy 2000 fpm. Need 130-140 on final with a short landing at the end -- same deal.
6 Altitude. The service ceiling is 16,800 feet and the aircraft is most efficient at 7,000 and above. I used to commute to Kansas and the ability to fly well at 15,000 was good for topping potential ice over the Appalachians. One December, I flew home nonstop at 15,000 in 5:20, landing with an hour and a half of reserves.
7 Utility. I am writing this from a small cabin perched on some rocks over the water, having arrived yesterday. A late-model Bonanza or Cirrus would have gotten us all here maybe a half hour sooner, but at greater cost. Which is best -- it all depends upon what matters to you. Speed can be important -- a Cirrus can get you from the DC area to California in a single day, but a Cutlass requires an overnight stop.
8 The dreaded landing gear pivots are a problem. I've had both replaced. It's a one-time issue over the life of the airplane. $10,000 sounds familiar, but I think it was total cost and for both of them. Getting the parts was not difficult, however. I would only buy an aircraft that has had the saddles replaced.
9 Insurance is another problerm. You may find high premiums as a low-time pilot in a retractable. If you don't have an IFR rating, that could also cause problems. On the other hand, I got mine with about 300 hours, 50 in type, a Commercial, and an instrument rating and my first-year premium was not bad. Thereafter, until I started instructing students, my airplane insurance was less than my car insurance.
10 Practicality. I would characterize it one of the most practical light aircraft for transportation. It is reliable and economical -- comparable to the cost of driving (if flown frequently) and much faster.
Paul
If a vanilla 172 suits your mission, go for it, but if you are thinking about trading up in a couple years, skip the 172. Trading up isn't cheap, from pre-buy inspections to sales tax these things add up quickly. If you think you'll end up with a retract or a 182, buy it now. Everyone says they won't, but most people upgrade avionics or something in their new airplanes, that money will be mostly wasted if you sell it in a year or two. 
