I usually use an older 4 card slot version of the
Chromexcel Bifold from Popov Leather, but found that it doesn't store enough cards.
Saw
this on discount for Valentines Day. Ended up paying closer to 35 USD for it.
Functionality: I've got 10 cards, a bunch of bills, and receipts that fit well. Because the storage is accessed in "landscape", it's pretty easy to get things in compared to "vertically" accessed cardholders.
Construction: I like how it doesn't have any stitching, but the buttons definitely add a bit to the thickness. Though the leather is full grain, it doesn't seem to take or hold a shine from lanolin/beeswax quite as well as the Chromexcel.