Micarta handles are indeed very beautiful. So, for a collector, the choice is obvious.
However speaking of hard usage... Hm, I don´t know guys but I´d say that Zytel is the more practical one. Let me explain my point of view:
1. Zytel is more lightweight
2. Zytel is cheaper to manufacture (and replace if damaged)so one is able to make a step up in steel quality
3. In opposition to Micarta, Zytel does not expand or shrink in cold, warm or moisty (wet)conditions.
The last issue is in my opinion the most important one. As speaking for myself, living on the Swedish west coast, the weather around here is often discusting, so my choice is easy. Also during winters, the temperature sometimes drops way under zero (Celsius). In an anvironement like this, Micarta easily cracks due to the strain.
Regards!