Preferred Coin Flip Size: 2x2 or 1.5x1.5 ?

When you organize your coins, which type of coin flip size do you use and why? 

Personally, I use the 1.5 inch size flips because you can store a lot more coins per page in an album, and thus save space. 

I use standard 50x50 for all my type coins. For my Japanese year collection I would like to use 38x38 for the smaller coins but unfortunately there seem to be no vendors in Europe who carry the flips and pages. I see them only in the USA and because they are cheap and bulky the shipping costs are prohibitively expensive. For very large and thick coins (like bullion) I usually use capsules and put those in trays.

More coins per album page is the main reason to go with 1.5x1.5 -  and if you use the red boxes, more coins fit in a drawer.

I am too entrenched in 2x2 to change now, whenever I do get a coin in a  1.5x1.5 I remove it.