I have previous experience with a GSXR 750, a CBR 929rr, and a sportster. The plastibikes were from my distant past and the sportster was more recent. I don't have the self control or talent for crotch rockets, so when I started shopping for bikes again last year I immediately started looking at stuff like the Fat Bob, night rod, and other cruisers. I eventually found that I didn't want to pay for a Harley and broadened my horizons a little. I ended up with a CB1100 because I felt like it was forgiving enough for someone just getting back on 2 wheels after a hiatus yet still offered enough in the way of challenge and excitement to stay interesting for a while. It's comfortable enough for a moderate commute (I do 80 miles round trip), especially after a seat upgrade and a windshield, but I don't think I'd ever do a 1000 mile day. Not that this bike was intended for that.
If an R6 is a scalpel and a road king were an 8lb maul, I'd consider the CB to be a 24oz ball peen.
I personally found the stock seat uncomfortable after about 20 miles. 40 miles was about my breaking point. The stock suspension is a little harsh, but significantly more forgiving than the sportster I've spent time on. My wife is comfortable on the upgraded pillion for about 40 miles, but after that she needs a stretch, but that's mostly because of the cramped pillion ergonomics. I think I could use about a 1" up and back bar riser. I'm 6' with a 6'-2" wing span and the amount of lean is either too little or too much. It's right in the uncomfortable spot for me and my back pays for it. Modifications and cargo options aren't a strength for the CB, but there's enough out there, for my tastes, if you look hard enough. If you need a seat, another member on here had good experience with
http://www.laamseats.com and my experience reflects his exactly. I got my seat back this weekend and did about 300 miles between Friday and Saturday. At the 40 mile mark my riding partner on his road king with deep sundowner saddle was having to stop. I was good to keep going.
I bought my CB on 3/1/14. 2 months and 3 days later, I'm still happy with the purchase, but I'm already looking at the future. If I were more comfortable on 2 wheels, I probably would have skipped the CB and went straight to a sport tourer, but things being as they are, I needed a more friendly platform to start with. This time next year I could be on a Triumph Trophy SE.