My wife and I are VFR pilots by choice. That said, we still do transcontinental flights in our Cherokee Pathfinder each year.
In the old "pre-XM" days, this entailed talking to flight service en route, and trying to visualize a line of storms that extended from "14 miles on the 157 radial from Fuddpucker VOR, to 27 miles out on the 340 radial from Bangaduck VOR" -- in a part of the country where you didn't know nuthin' about where the VORs were. In other words, en route weather was nearly useless, and we spent a fair amount of time on the ground waiting for weather to move through, simply because we couldn't accurately tell what lay ahead.
Now, we bring up XM on the 496 and WATCH the weather develop ahead. Or not. It's absolutely marvelous, and has allowed us to complete flights that would have not been possible before. It's also told us when to land and sit it out.
For example, we were droning along from Iowa to Sun N Fun a couple of years ago. We had to wait for a HUGE late winter storm system to move on through before we could depart. This low pressure center was trailing a front that stretched from the Great Lakes to the Gulf of Mexico. With XM on this 6.5 hour flight we were able to see the storm track several STATES ahead, determine their rate of drift to the East, and set our course accordingly so that -- by the time we arrived -- we would be in the clear all the way. This saved us significant time, and made for a more comfortable journey.
Another example: We flew to Wisconsin one fine day, and their was a line of low clouds between us and there. It was good VFR beneath the layer, but bumpier than hell. Normally, as VFR pilots, we would not fly over a solid overcast -- but with XM we were able to see that the overcast was merely a "stripe" about 25 miles wide. Rather than ducking underneath into the turbulent air below, we were able to stay VFR on top.
Just as depicted, in ten minutes we could see the clear ahead. This made for a faster and more comfortable flight.
Another example: Flying to Texas, we could see a line of storms ahead over Oklahoma. These were typical summer storms, with no "line" associated with them. We call them "popcorn storms" in Iowa, and they are easily circumnavigated -- but only if you KNOW there's nothing building behind them.
With XM, you know. The flight was easily and safely completed, whereas in the old days, we probably would have needlessly landed.
We live in amazing times. There are three things that have changed EVERYTHING about flying since I learned how to do it:
1. GPS
2. ANR
3. XM
We wouldn't launch on a cross-country flight without all three of those things anymore. It makes me wonder how we used to fly without them.