Great fixing method, and personally like the lighting effect. The only concern is dust being heated by the halogens, sticking and burning into the ceiling. Such is life with physics, but try explaining that to HWMBO.
To combat this, keep a radiator roller handy. Jam a splinter, or bit of wire, between the roller and the shaft it sits on. Dip in warm soapy water, and wring out until damp. Give ceiling a wipe down every few weeks.
Do not under any circumstances get caught doing this. This can only lead to the dreaded "Ahh.. while you have the stepladder out.." phrase. :lol: