jaydawg - Welcome to the forum. It is great to see you jump in with such an interesting question/discussion. My own opinion is mixed (pro & con), on the choice of using fly wallets with felt pages. I love them, for their aesthetic appeal to fly fishing tradition/history (warm leather/soft pages - there is something very positive about the tactile feel of the leather wallets). For me, the leather fly wallets harken back to the nostalgia/traditions/equipment used by our predecessors. I just love the look of a well used leather fly wallet. I have seen/handled/admired the one used by Pete Hidy (Lance's father). It is a thing of beauty...
On the con side, I agree with Jeff (Mataura mayfly). From a practical standpoint, the modern plastic/foam boxes have many advantages. The main advantage, to my mind, is that the modern materials are non-absorbent. I have a nasty habit of falling in (
William - stop laughing at me...
), wading too deep (
I am not as tall as Hank 
), or simply fishing in the rain (
when any sensible person should sit home). The result, is often wet equipment & fly boxes. Foam fly boxes easily dry out over night, while felt/leather wallets could stay damp wet for a couple days. Not good, in my personal opinion.
Do not worry about the hackle getting squished on wingless wet flies. The hackle tends to be very soft (even softer once it gets wet). Soft hackles/wingless wets/flymphs are very forgiving about being compressed. Heck, they may even fish better, from the abuse. In other words, they may serve as a better insect imitation if the fly is a little bedraggled.
In the world of fishing flies, "pretty" is nice to look at, but "ugly" gets results...
Great discussion. I look forward to your participation in the forum. Questions/discussion/information is always welcome.