Yep, I do.
I noticed it developing after just the first 100lb, but it's just something to be expected when losing as much weight as we have.
There are methods for diminishing/reducing it, such as increased strength training, lotions, drinking tons of water for elasticity, and contour surgery.
Then, of course, your age and genetics come into play.
For me, I'll most likely be looking into surgery once I've reached my goals and established a workable maintenance. I have talked to my doctor briefly about it earlier this year (although I was at the appointment for something different). He said I could probably look into consultations right now, so maybe I will - just to get a base understanding of the cost, risk, and procedure(s) required.
I've looked at several before/after pictures, and browsed dozens of youtube videos related to loose skin.
One interesting thing a patient said that has kind of stuck with me is to find a surgeon with a bit of an art background, since they're generally more understanding of the human body and it's intricacies. Hence, they can 'sculpt' you a bit better from what I've read.
I'm sure most experienced docs will do fine, but it is a big decision and one that will affect your appearance for the rest of your life.. so any suggestions/tips are worth noting
I would guess I probably have ~10lb or so of loose skin in my mid area.
I'd probably be at my goal weight if I had it removed right now

lol