I made a poll about this already [
Link] but I'll give you some feedback here.
You should be able to see which books I've purchased by checking out my profile.
First, a little about my tastes:
I have a strong preference for Vanilla, especially cute/happy stories.
I also look for exceptional art. Boring styles and excessive same-face may put me off.
I generally avoid group, forced, NTR, but I can stomach them on occasion.
Most other tags don't affect my decisions.
My favorite purchases:
Porno Switch by Hisasi - Overall bloody amazing art, characters, and writing. This will always be a favorite of mine.
PuniKano by pyon-Kti - Beautiful art, really really tasteful stuff.
Love Ridden by NaPaTa - I've rubbed too many out to these chapters (thanks FUKE) to not buy it.
Other mentions: These are very obviously very popular but less suited to my tastes.
Renai Sample by Homunculus - It's Homunculus' and FAKKU's first publication.
Peachy Butt Girls by Bosshi - A FAKKU bestseller. Seems there are quite a few assmen in the community (but the girls are pretty busty too if you prefer boobs).
TiTiKEi by ISHiKEi - Another widely popular book. Lots of color pages and everyone's favorite jealous, STACKED imouto.
Thoughts:
I mostly purchased these books because I felt it was the right thing to do. I've enjoyed hentai for a long time but it wasn't until recently that I realized I'd failed to give anything back. I truly consider myself a hentai enthusiast. I read hentai almost every single day, often spending more than an hour enjoying this stuff. The artists have earned my money, and I don't feel the slightest bit wrong about rewarding them. I don't think this needs to be said, but artists are fairly compensated when you make a purchase. It's legitimate.
FAKKU Books are produced at the highest quality I've ever seen for manga/hentai. It's done right. It's beautiful. There are very few, if any, imperfections. FAKKU really works hard to do it right and it shows. You can't get a better manga experience anywhere else right now. You get DRM free download options and the online viewer is pretty good too. The physical books are great quality.
There have been rare occasions in which books were damaged during shipping but those are almost always the post's fault and Jacob has offered to replace those in the past. There are also outrageous shipping costs to locations outside the USA (we hope this will change eventually). You won't have that problem if you order via Amazon, but you can't get a digital copy if you purchase through Amazon.
It's uncensored. Working directly with the artists allows FAKKU to get a hold of the original artwork, untainted by black bars and blurry spots.
Ultimately I'm repeating what FAKKU is selling. I'm here to say that as a customer I feel they really delivered on everything. They're taking hentai seriously and I really appreciate that. Everything's exactly as advertised and I couldn't be happier.