Hi,
Unless they have changed things since we were there last week, on arrival you are given a sheet of paper with meal times in the buffet restaurant:
Breakfast - 07.30 - 10.00
Lunch - 12.00 - 14.30
Dinner - 18.30 - 19.30 (early sitting) or 20.00 - 21.00 (late sitting)
One of the dinner sittings is highlighted and you are given a green band if you're allocated the early sitting or a blue band if allocated the late sitting. Our friends wanted to move from late to early sitting but weren't able to until 2 days into the holiday as the early sitting was full. We stayed on the late one but had no problem going in a bit early (about ten to eight). You don't have to arrive at eight (or half six), just between the times stated.
You are also given two slips of paper on arrival, these are your reservations for the Italian and Portuguese restaurants.
We didn't try to change the our reservations for the speciality restaurants, can't remember their opening times but our times were 20.00 and 19.30, if you weren't AI and wanted to buy a meal I think you could go in any time that they were open. I know that one family's reservation was at 19.30 and when they asked if it could be made earlier they were told no as they were "fully booked" (apparently only five tables were occupied....)
So regardless of what First Choice say there are restrictions on the times that you can eat your evening meal!
As far as the food is concerned, we were happy with the quality and choice in the buffet restaurant, although other guests weren't (not sure why....). The Italian restaurant wasn't particularly impressive, quite bland in fact.... but the steak in the Portuguese was lovely (but they ran out so only one of us go it!) and the chicken wasn't bad either - watch out for the super spicy piri piri sauce!
The building work at the new pool will only disturb people using the little pool at the very top of the complex, there is a kiddy pool by the main pool you can use instead if it gets too noisy so I personally wouldn't let this put you off if that is your main concern.
Happy holidays!