This is very confusing. Either it fits or it does not. Who is right then?
Well in fairness to both posters, it might depend on the tyre fitment.
Regardless, any full size wheel is going to seriously intrude into the boot space (and there's not that much of it to start with).
IMO it's not worth carrying a full size spare, but I'd never go out without a space saver. That'll keep you going if you get a puncture and you generally won't be that far away from somewhere that can either repair or replace the full size tyre. A spacesaver may look horrendous, but if you respect the limits, it's perfectly safe to use until you can get a proper repair.
Looking back over a lifetime's motoring, I'd say I've needed a spare wheel about once in every 100,000 miles. In almost every case, I've needed to use it in the most challenging, adverse conditions, but I've never yet been left stranded by a puncture. I doubt any (save perhaps one) of the failures I've experienced could have been salvaged with a can of squirty goo.
If you use the car a lot might be worth having a full size spare as well as a space saver, but the place to keep it is in the garage, not the car. It gives you the flexibility to fix the damaged tyre on your terms, not those of the nearest garage.