I find reading from a 320x320 screen not to be significantly better than from a 160x160 display. Sure, it looks better if you put them side-by-side, but for the purpose of actually reading
texts, it makes no real difference to me. I can honestly say my reading experience has not improved since the days of the IIIc.
Actually, the Z22 can be had for approx. €110 if you look around on eBay, so my original statement about it being too expensive does not hold. That said, the T|E2 for €150
would be a better buy.