I need more space for flies and would like to hear what anyone thinks
would be the better choice choice in a fly box.

I've looked at the following boxes, but can't decide which one is
right. Flies are nymph and dries for trout, 14 - 18 mostly with a few
larger flies for Stones 8 - 10.

Scientific Anglers X System

CF Design 1506, 1506F, and 3588

TIA for your help.