I was about to say that, the seats in the 172s are horrid.
The FISA LEAN is just a Grammer E3000 Desiro seat on the cheap, almost but not quite as good. Quite thick backed, though, so bad on legroom unless you have skinny legs so can put them together and forward into the "niche". A nice idea but not the best design. Comfortable in a table or priority row though.
Bit In Bold - Really? I wouldn't say they were my favourite seat, right now that is the First Class seat on GWR in their 80x fleet. I haven't any major complaints about the seats on a 172 though, I've spent plenty of time sat on them in the time they've been on the Birmingham to Hereford route, and not insignificant amounts of time on them since they first entered service.
Thankfully I don't have the issue of legroom in any airline seat, with possible exception to those on a 150/1. I haven't used an airline seat on that class in a long time, so I can't comment fairly. I wouldn't say my legs are skinny, good gravy no. They're not enormous either! I often prefer the airline seats, just so I don't end up clashing with someone sat opposite me.
I've still to try the 196s, and indeed the 197s. So my opinion on them remains as neutral as is possible. I already like them for the colour scheme, so there is a bit of bias, but in terms of the journey I fully expect to make a balanced opinion. I'm surprised I haven't gone to try one out yet!