The keytronic you have seems to be a membrane switch. If this is your first mechanical keyboard, I think the feel of the mechanical switches will greatly overshadow any difference in the keycaps.
If you read around, you'll find great debate about which keycap material is better. Some prefer the feel of thick pbt, gmk abs, etc etc. All I can say is, you never really know. I thought I really preferred doubleshot abs, but after trying out thick pbt set, I liked it a whole lot better. Get your new keyboard and stick with it for a month before you change anything.