Canvas Eagles is an "upgrade" of the Blue Max for Miniatures rules that were the last thing GDW put out on the game before going out of business. Some errors were fixed and I agree, having many more planes-- and the earlier war planes and a real selection of two seaters-- is nice.

I have played BM/CE with 3 different "flavors" of altitude rules, varying from 5 levels of altitude to 10 levels to 24 levels. While it does add some "realism" and bring in some sigificant airplane characteristics-- like good climbers or good divers-- it adds a great deal of complexity to the game and I don't think it adds a lot more fun.

Wings of War is adding altitude to it's next rendition (Burning Drachens, due out any time now). As with the other games, altitude will quadruple the amount of rules involve and I fear will more than double the time it takes to play the game and make moves. I don't know if it will really make it a more "fun" game.

Sopwith is a rare and odd old WWI game which is also a lot of fun, but "Advanced Sopwith" put a simple 5 level altitude rule and it "added" a little but also cost a lot.

I am not a programmer-- i should think adding even the most simple blue max altitude version (very low, low, medium, high, very high), which had-- really-- only 4 levels (since few planes could go to "very high" and those who could get that high could not get BACK up there once they dropped down) would still be adding a lot of difficulty to the game. Imagine the game map you see now with planes on it and try to figure out--graphically-- how to show planes are at different altitudes. Seems a bugger to me.

I have a full set of Canvas Eagles charts and quite a few 1/300 minis to use with it-- and I never use altitude any more. It just "costs" too much time for not enough return pleasure.

Just my opinion.