They are a pain to get off unless you are very very lucky. Most of the bolts will be correded to the bush casings. It's best to write off all the trailing arms and figure on replacing them with a set from Matt either with stock bushes or Nismo ones if you're feeling flush. I would also write off the discs and pads and also expect to have to re-build the calipers as they tend to have a habit of siezing when not used......again, you maybe lucky but don't be surprised if you getra nasty whip from the rear under heavy braking.
As for braking performance, not much different from drums. Initial bite is less being a disc.......the only advantage and reason for me upgrading was they don't suffer from heat buildup on a track, so give more consistant braking. If this is your motivation then it's worth it in the long run, if it's just for looks it may prove to cost you a fair sum to get it all setup and working right.
Just so you know, as I did this many years ago and re-built the rear axle last year.