My wife is a little more comfortable on the GL, but not a lot, and so being as nice as she is, doesn't mind staying on the ST. Just as long as there is a top box (trunk) back there, and I'm in front, she is happy.
There is an aftermarket cruise contol you can get from Audiovox (the CCS-100), new for at or under $100.00, depending on where you get it.
I thought the FJR was too small for me, especially if I put my wife on the back! Did not consider a BMW due to the lack of dealers in my area and the cost to maintain it. Even know a former BMW club president that sold his beemer due to the maintance cost and got an ST.
Weakness; the ST does not have the alternator of the GL, so you must manage your add on stuff appropriately (I have LOTS of stuff on my ST), but manage just fine. I wish the ST had an "OD" light indicator.
The ST is quick, handles easily in the twisties (much more so), extremely fun to ride! I love the electronic windshield, but wish that the OEM shield was a tad bit wider, thus, I put on an aftermarket shield on and am very pleased, more so than on the GL.
On the ST, you do lean forward more, more like a sport bike. I put on handlebar risers on and feel almost like on a GL, but not a straight up. This, IMHO, is good, as when on the GL, I would have a tendenacy to slouch down and get a sore back, and I needed the backrest on the GL. On the ST, I do NOT need the backrest. Some folks think that those that ride bicycles where they lean forward must have a sore back, NOT SO. As long as you get a bicycle that is the correct size, it is very comfortable. For me on the ST, the issue was the leaning forward on the stock bar angle, I had too much pressure on my wrist, the leaning forward was fine otherwise. With the bar risers, I'm not leaning forward near as much, the pressure is off my wrist, but I'm leaning forward enough that it keeps my back posture perfect.
As for leg comfort, neither the GL or the ST had enough for my knees, so on both, I had to add aftermarket gear to stretch out for those all day rides. My knees feel just as comfortable on my ST with aftermarket pegs as on the GL (which also had aftermarket pegs).
As for long distance riding, NOT A PROBLEM on my ST, I LOVE IT!
Hope this helps, good luck which ever route you take.