I can see you are travelling without kiddies so a long stay in the excellent QR lounges in Doha wouldn't be a problem for me; maybe even an incentive for me to book QR Just make sure you don't book an 'unbundled' J fare.

Plus, you could also go into Doha for a while and do some lounge time as well. I would personally prefer the option to split the time into 2 flights, but it really depends on your personal preference.

The inflight experience in Q suites is in my opinion still better than with BA (assuming you get Club Suites, otherwise QR is miles ahead).