There are aspects of the rostering which are considerably worse than locos. Having watched a friend's roster for most of the year, the standard pattern does seem to be only two days off in a block (though quite often with early finishes on the last day following night flights). The objective of Carmen is bid satisfaction, supposedly, and bids don't seem to reach the levels of satisfaction that are claimed for Carmen on the whole across the company - which are supposedly 60% - my friend seems to end up with only one of the low-priority bids only being granted each month. He came from a low cost shorthaul airline where he was working on a fixed pattern with a minimum of three days off in a row
Also, his hours have been run through relatively quickly - a lot of US trips, the lack of "bid satisfaction" meaning that the low-hours-density-longhaul trips (Mauritius, Tokyo, Rio) weren't given, resulting in a very light roster now (three trips in a month). Uncharacteristically, this has given extra days off, which is a treat!
There are other aspects of the job which would be relatively easy to improve, but which BA seems to have little interest in doing so, it being mixed fleet rather than WW. For example, free breakfast in hotels, free wifi in hotels, the ability to put crew bags in the hold on shorthaul days...