We went from a tank style system to a combi about 6 years ago - I thought combis were all the rage from an efficiency perspective.
Old boiler needs to be moved out of a bedroom to make storage space and I am doing the kitchen up anyway so it is ideal to move it into a kitchen and even mroe dieal to get it into a small wall cupboard.
As for Bosch - just chose them based on reading reviews etc. I've spent enough time I want a Bosch Compact that I am not going to reconsider another one! Plus I have made appointments with Bosch approved installers now. Either way I doubt Bosch is the worst and even if other makes are better I imagien the Bosch is good enough.
I'd never even heard of WB until I started looking into a new boiler.
In terms of future proofing I meant if we have more people - so more liekly to have someone using upstairs and downstairs taps as oppsoed to a whole new bathroom.
You out say you are basing your decision based on the reviews of the Worcester compact, there can't be that many out there as it was only launched 2 maybe 3 months ago so all the reviews on it will be good as nobody has had to live with it long term. I also wouldn't go too much on reviews of it's older boilers as this is a completely new design,
but as you've said it's what you want and I admire you for sticking to your guns