Not sure there's a lot to choose between the two, to be honest, apart from the obvious.
So the 2.0 a bit more powerful, a bit more thirsty, and a bit more expensive.
I've got the 1.6 (in a Passat), but kind of wish I'd gone for the 2.0, but I needed a car in a hurry, and there was a 1.6 available more quickly, and the extra cost for the 2.0 seemed a lot just for a slightly bigger version of the same engine.
Maybe one reason is because I had the 2.0 in my previous Passat, and if you've been driving it for several years like me, you're going to notice dropping from 140 bhp to 105 bhp.
Don't get me wrong, 99% of the time it's more than adequate, but on rare occassions you just wish it had that extra bit of grunt.
I very rarely use the 6th gear, for example, and can go weeks without using it, and would only really engage 6th on a reasonably clear road with a 70mph limit.
Problem is that much slower than that, or if you have to slow down for overtaking trucks etc, I always feel the need to change down gear. So rather than that, if the motorway/dual carriageway is busy, I'd tend to keep it in 5th. Same on slower roads, where I tend to keep it a gear lower than my 2.0 Passat, which obviously detracts from the fuel savings you'd hope for from the 1.6.
On the other hand, I'm maybe just being a bit paranoid, and I suspect most drivers with the same engine will tend to stay in a higher gear than me.
But although the 1.6 will pull from 1,500 rpm in 6th gear, it won't do it very quickly, and there's something in me that doesn't like using an engine in that way, and prefer to keep the revs a bit higher.
Doubt if it's doing the engine any real harm, but I prefer not to maybe overstress it by pulling at very low revs in a high gear.
But didn't really feel the same way with the 2.0, and it would pull more cleanly and efficiently from 50 mph in 6th gear, say, so I felt more comfortable keeping it in a higher gear.
Another point, though, is that I think the newer models are more highly geared, so if I had the newer 2.0 then I'd probably end up in a lower gear than with the old 2.0 anyway
Maybe another reason is that I'm driving a tad slower than I used to (more cautious in old age, and all that
) and the A-roads I mostly drive on have been reduced from 60mph to 50mph, and there are a few 40mph stretches as well. So both these factors could also explain why I'm tending to use a lower gear rather than just the move from the 2.0 engine to the 1.6.
Bet you wish you'd never asked now