iFixit is so great. I recently paid £200 to a charlatan who bodged a phone repair, so I took the leap and attempted to fix the bodge. iFixit had simple photo guides, it was a piece of cake, and I'll never send my phone away to get fixed again.
I don't trust my stuff with others, but that's probably because I can fix everything myself heh.
Last couple of times I had computers fixed, I got a missing RAM stick and a piss poor BGA reball job that failed within a month. They probably didn't have the best tools, but I paid a lot and they didn't even fix it for free a second time. I just replaced the system board.
Correct. In my experience of working at a cellphone repair shop, we looked up most Android repairs on iFixit and/or YouTube before quoting a price. If a tutorial suggested that there was a high likelihood of breaking a given part (usually the screen) during the replacement of an unrelated one, we would throw the cost of that part into the initial quote. Apple products are standard enough that the repairs which can be done were well known to everybody, and we didn't have to research those before giving a quote.