I've been there in the Mormon church. I was never disfellowshipped or excommunicated, it was a fairly typical teenage "major" sin, but it was eight very painful months. And guess what? Despite all the heartbreak and guilt and work to be "forgiven," I repeated the sin later on. The Mormon church would say that was because I hadn't fully repented before, and that therefore I still had to repent of the old one and the new one.
Nor was it a process of comfort, redemption, and positive change. Nor was my sorrow so much for what I'd done as for all the pain it had caused me. I knew intellectually that it was wrong, for sure, but actually feeling it was wrong for the sin itself was always just beyond my grasp.
It also confused me why the bishop determined when I was "forgiven." It made me wonder if I could go my whole life seeking forgiveness from God but never finding it, if the sin was bad enough or something along those lines. In fact, the Mormon church says the answer to that is yes, it is possible, usually in the case of murder or an extremely terrible sexual sin, like rape. Or at least, people like Spencer W. Kimball, who wrote the handbook of forgiveness, say that.
What bothered me was the manner of church discipline. I tried very hard not to question it while I was a member, but I quickly realized after I left that it bothered me. I found places in the Bible where we were told to confess to Jesus and he would forgive. I never found anywhere in the Bible that it would take a long period of time to achieve forgiveness. Instead, it seemed to be a gift freely given.
Discipline in the Christian church is also far different, and outlined clearly. If there is an offense/sin serious enough to merit interference, there are steps to be taken, but the actual forgiveness is ready to be given the moment the sinner seeks it, not eight months after a lengthy process. Sanctification takes much longer than the actual forgiveness, of course, but that is much different.
In the Christian church, we are to that we are to judge fellow Christians. Not in an arrogant or self-righteous way, of course, but more like a judicial system--we are to call them out on their sin and beg for them to come to repentance. This is first to be done individual to individual. Whether it is one church member to another, or an elder to a member, or elder to elder, it should be one on one (although in the case of members to elder, there should be more than one member, since elders have such a tough job but are held to higher accountability). Then, if sincere supplication for repentance and outlining of the sin committed does not cause the offender to repent sincerely, then more than one person is to go together to try to do the same thing. I just imagine a few loving people sitting down someone and saying lovingly and carefully, "you need to consider what you've done. This is what we're seeing. Please turn from it, its not good for anyone, especially you." If that fails, more public or firm discipline might be needed, such as presenting the situation to a larger group of believers or having an arbitrator or mediator for the offended parties. And finally, if all else fails, the one at fault is to be basically excommunicated out of love, in hopes that they will find that when their sin is not welcomed or allowed, they will realize what it has done to them and will finally repent and return. The moment true repentance is displayed at any stage, the guilty party is to be welcomed back, comforted, and helped immediately.
Does that sound like Mormon discipline? I went to my bishop and confessed my sin, willing to repent (although, not having given my life to Jesus yet, it was doomed to fail or not be full at some level) and instead of saying, "thank you so much for telling me, know that God forgives you, now let me help you in overcoming this," I got, "You are not worthy to take the sacrament or attend the temple, and you must do this this and this, and we'll see after a while how things are going, because forgiveness will take time...oh, and read The Miracle of Forgiveness."
I can attest to the huge difference between these two things. While I've never experienced formal church discipline as a Christian because its never been necessary--are major sins have gotten left behind since becoming a Christian, although I really only had one "major" one--I think many of us have experienced what its like for a friend or loved one to talk something out with us, and we've had to admit we were wrong, and that friend or loved one was ready to repair things with us and work with us the moment we admitted it. I certainly think that good friend or loved one is a far better representation of God's forgiveness than the Mormon church is.