I did the cambelt last year, and today half way through putting in a new GTA clutch and 2.5 flywheel. Fortunately on both counts I employ a friend of mine and his facilities and we both crack on together. Fortunately he is a home based mechanic and is a bit of an ed china so has full workshop and every tool under the sun.
Would I take the engine out? if doing all the same time and you don't have a good workshop probably yes. Getting the gearbox out today was a *****. You have to dismantle everything, and I mean everything to get the box off. Exhaust downpipes, rear exhaust manifold, all engine plastics, undertrays, clutch slave, hundreds of electrical blocks, starter motor ( which is in the craziest place possible and needed the rear manifold taken off to get to the last bolt), extract both driveshafts, split all front suspension. We used the car lift and two block and chains on an overhead beam to lift the engine and box separately. God only knows how you would do this on the floor. 8 hours in we have just put the box back in and ready for reinstalling all the other bits tomorrow. If it was a clutch only next time I will take it to autolusso as their prices for clutch replacement, seem good for the price to grief ratio. This job is grief!!!!!
We did the cambelts last year, admittedly using the tippex and jamming bolts in the cam sprockets to stop them turning method. I know it sound terrible but its ok if your confident at it and saves about 3 hours and saves on cam cover gaskets etc. Access again is crap and it took us probably 6 hours start to finish including making up special tools like the tensioner as we went along.
Only downside of removing the engine would be aircon, water stuff etc. Otherwise take it out access is near impossible with a workshop, I guess nigh on impossible on the drive.
Good luck which ever way you go.