We may earn a commission from links on this page. The Xteink X4 is a wallet-sized e-reader from China that has attracted a cult following of tinkerers online for its no-frills charm and crisp 4.3-inch display. When I reviewed it last year , I had a few minor complaints, but "too big" definitely wasn't one of them—not surprising, given I was already an adherent of the phone-sized Boox Palma 2. But now that I have tested out the Xteink X3, the X4's even tinier brother, I can't help but wonder if there exists an e-reader so small I won't prefer it. Xteink X3 E-reader $79.03 at Xteink Shop Now Shop Now $79.03 at Xteink Xteink X4 $69.00 at Amazon Shop Now Shop Now $69.00 at Amazon SEE -1 MORE The X3 has a 3.7-inch screen measured diagonally, which makes it about 14% smaller than the X4; including the bezels, it has an overall footprint that's roughly 20% smaller.…