… on my Vectra.

Anyone suggest why I really shouldn’t?

I know the procedure & am confident with a bit of simple mechanic-ing (do all my own bike servicing & maintenance).

Should be pretty straightforward, but are there any pitfalls I should be aware of?

The only issue you might have with the rears is that you’ll need a piston winding tool to wind the caliper piston back it.
You can sometimes manage without one and use a combination of pliers, screwdrivers and brute force but it’s not always easy!

As yourself honestly if you are bit mechanically inept…. 😀

some hubs/disk attachments use ‘one shot’ bolts/nuts that can’t be retorqued – might be worth checking if this is the case with your car.

buy a haynes manual for you car. That will list any caveats with your particular make / model.

Never had a problem myself.

Or ask on an internet forum and get random answers.
You’ll be fine, what could possibly go wrong?

A mechanic will charge a fair bit for his time, but then he does this all day so will be about three times faster than you.
I used to do all this kind of stuff myself when I really had no choice, but to be honest I hate working on cars and would rather have the time for other things.

So long as you have the correct tools (torque wrench in some cases, not sure on that car) then it’s a half hour job, maybe an hour if you’re new to it. I’d rather save myself the 50 quid labour charge and spend an hour getting to check over my own car than trust someone else to do it and pay them for it. Everyone has their own weightings.