I bit the bullet last night and purchased the PMDG 777 add-on for Microsoft Flight Simulator X.  It’s nearly $100 and worth *every* penny.  Here’s some initial impressions:

• I now know why PMDG charges what they do.  From the installation experience to the docs and the actual flight, it’s clear they made a silk purse out of the sow’s ear that is FSX.  My older PC with a low-end NVIDIA card handles the aircraft without breaking a sweat.  It’s every bit as usable and fun as the default C172.
• I was able to make a flight from Memphis to Springfield without much of an issue within 10 minutes of finishing the install.  I already knew the basics of FMC programming but this was my first real exposure to it and it’s very logical and easy, once you have the right mindset.
• I can see that this would be easy to fly for both long and short flights.