I've definitely had difficulty when replacing a scene I know worked in some way (opening scene hooked agents but needs to be changed for some reason; betas loved a scene, but it doesn't work with other revisions made), and it can be paralyzing. Sometimes it's paralyzed me to the point of not being able to fix it, but others, I eventually just worked through it. Usually I feel, while writing, that the new scene isn't as good as the old one, but eventually it becomes part of the story and I see its worth. I even had one novel where I changed the opening and asked critters which was better, and they thought the new one was better, even though I thought it hit a bunch of cliches.