FR, I disagree with the limit of 110". Yes, it's a generalization, and if you are generalizing about the typical room with pizz poor light control (most rooms, even if they say "oh I have full light control"), ok then I agree with you. I have unity gain in mind btw, but put in retro reflectors or whatever, I think 110" can be blown away, personally speaking.
JVC has historically had better brightness than both Epson and Pana when calibrated. You don't see people saying that Epson/Pana have a hard limit at 100" or less, for discussion's sake (or am I wrong about that).
For full disclosure, 3D is about the last priority I have, and even with a 42 degree viewing angle from the front row, I don't care about any kind of 4K upscaling. 4K native, ok now we're talking, but I doubt I could afford that for a long time anyway.
Yes, it's just my anecdotal opinion. But I've seen the step by step improvements to my setup from adding side curtains, to adding black carpet in front of viewers, to painting ceiling black in front of viewers, etc. It was never subtle with any given step.
Given my setup, with the above in mind, the one improvement I actually wish the most for is improved black detail. Color accuracy would probably be second, and finally brightness third. I use a 126" DIY Seymour, see below. (I believe this pic is with all track lighting pointed forward for the pic, with use of flash, otherwise you can't make out nuthin' really; here you can make out some speaker drivers through the false wall on the right). Anyway, I can totally appreciate your concern about black level/detail, because with the more time that passes with my system, the more I understand its ultimate importance. At least for movies anyway, not so much for an NBA game.
But, as with you, I'd either be interested in the entry level, or perhaps the 48 for the full blown CMS, something I've never enjoyed. I still don't think it's worth it yet for me to upgrade, of course a personal judgment with all things considered. Personally with any future purchase, I only foresee waiting out all the consumer feedback, fully intending to hopefully catch an AVS b-stock sale of sorts. Saved me 33% from the best price I could find otherwise, the last time I did that. (I just read they have a 3 hr guarantee or something, full refund on return if unsatisfied, but the return shipping is on your dime.)