Well I pretty much spent most of the indoor season experimenting with F1L props - different widths, different spars, different pitch, mounted on top of spar, mounted on bottom of spar, 14", 15", you name it! I've settled on the 15" 26p prop, I have one really good one and one almost as good one (after making over a dozen). I've been able to do around 13 1/2 min several times, with 13:42 being the best, so we'll have to pick it up from there next year. First photo is end of the season shot of one of my F1L's - I've gotten good at skimming the lights and didn't lose any planes this year, so I really didn't even need my second F1L! same thing for A6 - I pretty much flew only one of the two 24" A6s.
I've been neglecting the A6's lately, so for the last few sessions I thought I'd finally get around to some side by side comparisons of the 24" and 20", field shot below. I 'retired' the 20" pretty quickly last year because I had the 24" built, but lately I've been thinking that maybe I did that too quickly and should take another look at it. First thing that struck me was that it was very easy to trim, just climbs right up there, no problem with high torque at all. If I was doing high ceiling flying, I might stick with it since it looks easy to get it up to 100' (I wish we had Columbia!). The 24" on the other hand, is trickier to trim, particularly for the burst, and I noticed that Tom also had burst problems all season with his 22", so it's finicky. You can get it trimmed to deal with the burst and climb out, but it's trickier and everything has to be 'just right'. However and most important, I thought the 24" had a nicer cruise, a little slower, and for the few flights I got in, the 24" always had longer times than the 20". Plus I've only gotten to around 6:45 with the 20", even though I haven't flown it much, but have done over 7 min (top of 7:26) with the 24" a bunch of times. The other thing that convinced me is, for two very similar props, the 24" typically has RPM of 340 or lower (down to 320 or less) - but RPM's for the 20" were around 370, just reinforces my conclusion from watching them fly - the 24" flies slower.
So that's where it stands. As far as the high AR stuff goes, I'd recommend that if you want an easy to trim plane, or are doing high ceiling flying (Cat 3 or 4), the 20" is nice, really barrels up there with little trimming effort. However, for 'low' ceiling flying (Cat 1 or 2, and maybe high ceiling), I think the 24" flies a little slower and has the edge. Given that I only have 32' of flying space at Teaneck, I'll stick with the 24"!
I'm usually too focused on flying to get any indoor video, but I recently got part of an F1L flight and the 24" A6 flying last week:
https://www.youtube.com/watch?v=6DHsLdXGOks