I don't like them, I find large flabby tits unappealing. Like yourself, I prefer the small and pert.
However, sometimes I get the urge to see a big-titted girl. Dunno why. But I still want them to be firm.
If you can find them big and firm and NOT fake, and everything else in order and in proportion, you've found the Holy Grail, my friend.
Once had a girlfriend who had the most wonderful pair of firm 34DDs on an otherwise fairly narrow frame. Lovely. But of course there was a downside, and in her case, she had a boy's bottom (which I hate). In my life, I've generally been attracted to short blonde women with big tits, but you often end up trading down in 'firmness'. C'est la vie.
