We just got off a British Airways 777-300 with suites in business class. Basically they are lie-flat seats with a door that closes for privacy. Wasn't any more comfortable than other BC products just more private. Interestingly, first class sears did not have a door. We flew BA 1st last year and despite the lack of a door it was very comfortable. That was a splurge paid for with points. We've also flown Qatar Qsuites a couple of times and they were excellent. Some of the Asian and ME airlines have some over the top suites that are supposed to be very nice. The best sleep and food we've ever had on a plane was on an older Turkish Airlines 777 with 2-3-2 seats with no privacy. If you didn't have an aisle seat you had to crawl over someone to get out. The seats folded into long rectangular beds with no enclosed footwells.
I have done many flights in BA Club suites and find them to be a very good hard product. In fact, BA is overall a good airline, the only problem being the transit through LHR T5 which is
always crowded both in the lounges and outside. My order of preference in terms of business class seats comfort from best to worst:
Cathay Pacific A35K. Although I hear that the new Aria suites are even better
BA Club Suites on 777 and A35K
Emirates A380 business class (although the bar at the back makes it worthwhile - see pic

)
Tie: United Polaris, Swiss business class
Emirates 777 2-3-2 business class long-haul
Emirates 777 2-3-2 business class short-haul (lumpy seats)
BA Club World yin-yang. Although I really like seats 3K and 7K in the 787s (very cozy)
Lufthansa business class: This is truly horrible and not worth the money.
I do not aim for status with any airline since I look for the best deals. However, even without trying, I usually mange to reach some level of status with United and BA. But now that United has raised the levels, I think this may be the last year as Gold. I got a huge number of Avios and tier points thanks to our recent Cathay trip so I think at least BA bronze is within reach.