I disagree that there is nothing but struggle for those who don't have to do a pre-op liquid diet. I did not have to do one, and I've done very well since my surgery.
The point of a pre-op diet is to reduce the size of your liver, to make surgery easier to perform. If your surgeon decides that's not necessary, then you don't need to go through that. Post-op, they'll ask you to follow their dietary recommendations, and work your way back onto solid food on their schedule.
The disconnect people here seem to have is they expect they'll have immediate restriction after surgery, and immediate, nonstop weight loss. When that doesn't happen, they freak out and get all stressed, they develop all sorts of negative attitudes, and they blame everything for not working as advertised. In truth, the first six weeks after surgery are primarily about healing, so your system can get used to the band being there, and so the placement stitches can heal up. After that, when fills start, is when you should be concerned about restricting your diet down a normal bandster level so weight loss can start Failure with the band is normally caused by people who don't know what to expect, and who make improper choices, and not usually because of a physical problem, or because they didn't have to suffer through a pre-op liquid diet.
The key to bandster success is following your doctor's orders, doing what you're told, eating right, exercising properly, and listening to your body's response to having the band in there. The key to bandster failure is second-guessing your doctor, not following orders, eating poorly, not exercising, and expecting the band to do all the work. Everyone has the best intentions with this, but the people who seem to have the most trouble are those who are least informed about what to do, and how to live with the band. It takes work, and it takes education. After that, the rest is in living daily with the band.
Good luck with your journey. I wish you great success!
Dave