As far as I understand it they are cutting down the centre between the muscles when they make a midline incision, but the recovery process is certainly longer with an open procedure than laparoscopic on average. As with everything recovery time can vary a lot from individual to individual and the best thing you can do to reduce your recovery time is to be as healthy and well nourished as you can before surgery - which is a big part of the decision process, I think, in not waiting too long. Which isn't to say it's easy to decide because I think there's a very natural reluctance to allowing someone to cut you open, plus worries about scars and taking time off work or study, the uncertainty of the outcome and the possibility of complications. It's almost easier to wait until you are so sick that you are sure you need it but that can put you in a worse position in terms of healing and recovering. I almost certainly did that with my first surgery - I'd been in pain for such a long time that I didn't remember what is was like not to be, I wasn't sleeping and couldn't eat much and became very malnourished. On the plus side it was completely clear that I needed surgery and, with that much scar tissue restricting my ability to eat or even consume liquids, I wouldn't have in all likelihood survived long without it. However I really suffered needlessly for a long time when it should have been clear to everyone that the strictures weren't going to go away, because they have no way currently to remove scar tissue except with surgery. And my nutritional state was really poor when I went for surgery which increases the risk of complications.
Anyway that's definitely not to say it's easy making the decision but those are some of the things you need to think about and try to decide whether you're at the right point for you to have surgery.
I completely understand the superficial worries too. I think I wore a bikini for most of the summer of 2001 just because I could because I knew I was having surgery in August...and I guess I must have thought that I wouldn't again but I have because honestly these scars don't look that bad. And, even if they did, no one else should care because it's not their body. I think the most important thing is you being okay with your body and ultimately being healthy is the most important thing. Plus I consider them battle wounds and that makes me feel differently. Anyway back to the effect on abdominal muscles - it shouldn't change the look of them at all I don't think, although obviously you will have a scar on your abdomen. I am speaking as someone who has never had amazingly well defined abdominal muscles though but if you look at diagrams of abdominal muscles (or someone with very defined abs) you can see the line down the middle and that's where they make the incision for an open procedure. Very rarely I think people might have an issue with the groups of muscles either side not coming back together properly but it can be fixed and it's not common after this sort of surgery - it happens a lot more for women after pregnancy. It's more just about holding off on abdominal exercises until you're healed well enough. Which might, just as a guideline based on my experiences of what my surgeons told me (although obviously you'd need to get the okay from your surgeon who can assess your readiness for exercise), be 6 weeks for exercise more than walking (I had a surgeon who let me ski at 6 weeks post op) but perhaps longer for targeted abdominal work. It really depends on the individual though - I had some slow recoveries because of malnutrition for my first two surgeries, and on my second surgery that probably led to a post-op abscess which meant a couple of readmissions, whereas some people have much faster recoveries. Kids seem to be up and running a few days post op! Even with an open procedure they'd expect to get you up sitting in a chair either later the day of the op or the morning after, depending on timing, and possibly taking a few steps, the next day walking down the corridor and so on. If you're healthy going into the operation and have a good recovery you can be home within a week.
I think that while adhesions very commonly occur and if you had another surgery your surgeon would then encounter them (they have to cut through them to separate the bowel and as I said it's a factor in subsequent surgeries), they don't cause symptoms most of the time. If you have laparoscopic surgery the risk of adhesions is lower but I still don't believe it's a large risk for an open procedure, in terms of having pain from adhesions and requiring surgery for them but we do have to balance all the risks of complications with the impact on our quality of life and the threat to our health from the strictures - there's the possibility of perforation as well as the strictures worsening. I don't think it's ever easy but I think it helps to talk about all the considerations, even the little things, because if we find that we can put some of those aside and it becomes clearer what we are really choosing between then sometimes you just know that it's the right thing for you at that point in time.