I'm not sure that there can be a standard answer on this one. I think there are a lot of factors that are going to play a role in how much loose skin you end up with - the big ones being age, how long you've been overweight, and just the elasticity of your skin in general. Over the last 8 months I have lost just over 100 pounds on IP and I'm actually pleasantly surprised at how well my skin has held up. I started at 272 and now am at 170. For reference, I'm 5'6" and 42 years old. I've always been somewhat overweight, and realistically have been over 250 for at least 5 years, with a few times I have dieted into the low 200s during that time period. My skin tends to be a bit oily and I've been lucky to avoid major wrinkles on my face - so far at least
The worst spot on me is my stomach. But considering my waist measurement went down 15" - I really can't complain! And I don't think it is bad enough to even consider having it removed. The skin is not noticeable at all in clothing, and the worst of it is covered by my underwear. I'm just starting to increase my workouts now, so am hopeful that it will tighten up some over the next 6-12 months. The main time I have noticed the excess skin is during a recent workout. I did a Barre DVD at home and was just wearing a sports bra without a shirt over it. When I was doing push-ups I looked down towards my feet there was definitely skin hanging down. When doing some leg work during the video where my leg was up in the air and my inner thigh was facing down, you could definitely see skin hanging down further than I'd like to see. My thigh measurement went down about 6" each leg. Remarkably, my arms have held up pretty well! So it is not the most attractive thing in either location, but certainly not enough to consider surgery.
I've started adding collagen into my routine about 6 weeks ago and now that I'm in phase 3 am starting jogging and doing the barre videos. I also do my best to keep the skin hydrated and lotion up after every shower. I'm not sure that any of these things make a huge difference, but I figure it certainly can't hurt.