Ummm... your maths is a LITTLE wonky...
The +2 food is ONLY AFTER Biology, and with a farm. If you kill the forest and add the farm, even with Biology, you get +2 food, -1 prod, -0.5 Health. Also, National Parks give +1

, so once you can build a national park you get +1 Health. So, in a national park city, by clearing the forest you get +2 food, -1 prod, -1

(if its beside a river), -1

, -0.5

-1 specialist. So... even if you use the +2

to turn into a specilist, by replacing the forest preserve with a farm you "gain:"
-1

, -0.5

, -1

, -1

(beside a river).
So, with the national park, even with biology, you lose ALOT by replacing preserves with farms...
My fav. combo is Heroic Epic + West point, closely followed by Heroic Epic + Ironworks... but I only use the latter when I have TONS of

ready...
Actually, I just realised I voted for the wrong thing >.<. Take off one vote for Heroic Epic + Ironworks, and chuck it in Heroic Epic + West Point

That will give the proper results.