I've been through two appeals myself on the receiving end, stupid I know. The first time I used the reasoning that I was repentant and the first commitee hadn't seen it, and I actually was repentant the first time. I told on myself, broke down and cried and apologized for my actions and it was all heartfelt. They disfellowshipped me and during the appeals commitee I was scoffed at and called names and told I was a prostitute against Jehovah. At the time I was almost engaged to a good witness girl and wanted a clean slate and had actually felt bad for the fornication that I'd commited 8 months earlier. After I was disfellowshipped, my girlfriend got instantly married to the first ministerial servant she could find. I was 20 years old when that happened and up until about a year ago, I don't ever remember feeling any worse about myself than the first disfellowshipping.
I can thank the elders in those first two comitees for starting me down the road that would lead me out of the organization. I got reinstated in six months and found that my girlfriend had married some other guy and then I decided to say screw it. I'd been a good boy for those six months, studying all my lessons and reading the bible for an hour each night with hopes of being a pioneer and an elder one day, blech. I started sleeping with a witness girl within a few months after I was reinstated. I was way to cocky and open with it and didn't hide it very well and basically got caught with her in my bed by my witness mom, who in turn told the elders.
I denied everything because I knew that there weren't two witnesses. And although they had only one witness and niether her nor I would give up any info about our relationship, the elders DF'd me anyways. I appealed it on the basis of no proof, so it didn't happen. The appeals commitee basically told me I was evil and said if someday I came back, maybe they could forgive me, but didn't know if Jehovah, the god of love, would ever be able to forgive me. The girl that I'd gotten DF'd for being with wasn't even given any reproof and we had the same story. As far as I can tell, unless you have high up connections that can help you out, then there is no need to go through an appeal unless you enjoy torture.