I have a lightweight full size 45. It carries like a dream! Not to muddy the waters further lol. Also have a ltwt 45 commander. If you don't plan on putting a TON of rounds through it ltwts are awesome.No I think the LW frame is more a difference than the 3/4 of an inch.
I know a 1911 is supposed to be a 45 but 9mm suits my needs including being economical. Think 9mm is going to be like shooting wadcutters in a k frame or larger.
However if you aren't going to carry it the steel frames are more enjoyable to shoot.