The dip stick is a bitch yes. I have had four fat arsed megs (only one 1.6) and here's what I have encountered.
-master cylinder makes a hissing noise from the front passenger footwell when it's on it's way out. Had a few of these.
-the 1.6 can be quite rough when cold, lurching about, not like the rs133 though.
-changing the front bulbs is a bitch, not quite the bumper off job my local stealer tried to charge me for. Found it best to take the wheel off to give a better angle.
-the dash can squeak, rubbing against the wind screen, this apparently can be adjusted.
-everyone I have had the drivers seat has squeaked if at its lowest height.
-the cam belt maybe due on the one your looking at (5 years) make sure the defaser pulley gets done at the same (the cam belt needs to come off to change this I believe) time to avoid the diseasel like rattle on start up.
-pameramic sunroofs can leak on the rear quarters. Mine was wet on the bit where the rear speaker are. Didn't manage to fix this before I chopped it in.
-check if all the speeds on the blower work correctly, there was a problem on the senics that this could cause a fire, something to do with the fuse pack. A mate of mines 2 and 3 blower setting didn't work and Renault fixed it contributing 99% to it although the car was 5 years old, this ment as he paid towards it the work was garenteed for a year by the dealership
For me the 1.6 felt underpowered ferrying the family about, the 2l is a lot smoother and we get the same mpg, more on a motor way due to the 6th gear. The prefect fit is the 1.9dci, had two of them, once remapped they can shift. Never had the 2l diseasel. Anyway your needs may not be the same, a to b stuff the 1.6 is fine.
We have a 2007 2l estate one that Is the current family bus, I plan to run this into the ground as it now worth sod all. been a cracking car, had no problems in 3 years of ownership.
We had a 1.6 five door before this that we found a little small (I found a chore on long journeys).
I had a 1.9 dci 120 3 door, which was faultless which I should of never of got rid of and finally a 1.9 dci 130 3 door which had everything wrong with it. Went though a new turbo, inter cooler, two clutches and a master cylinder. That was all before I had it remapped, it managed 150bhp/250lb as standard and something like 180bhp/320lb once remapped.
Rant over.