It has always been my impression that neither Darcy nor Elizabeth really knew each other all that well. I won't toss words like love around as i am not sure they are all that accurate at the time Darcy made his 2nd proposal. What they had established, i think, is a fundemental understanding and admiration for the others character. It was during the engagement period, i believe, that admiration and respect developed into love. That period cover about eight weeks and with almost daily contact and conversation, i think it's fair to suggest that love could develop.
Whether it was a good or bad or indifferent or great match is, i think, something we have to allow JA to determine. She, who knew the charactyer of her times much better than ourselves, did not hesitate to present it as a reasonable outcome. What we are also left with is that Darcy's main faults are an overblown sense of pride in his station and extremely poor manners. Both got humbled by Elizabeth - quite decisively.She, on the other hand, was immature and vain with an overblown sense of pride in the correctness of her judgement. That was also humbled decisively.
