I have WSOP, EPT (older and newer), WPT, and titanium decks from Fournier. I'll see if I can take some closeups of each. But everyone's tastes are different.
Finally got a chance to do this tonight.
The players
WSOP "Breakout", EPT v1, EPT v2, WPT, Titanium. All are coded as 2818. The Titanium have thinner pips, though.
The reds are "security" red (darker) for the EPT v1 and Titanium line
The are all within 1 card thickness. I think the WPT cards might be slightly thicker.
My phone won't focus up close, so getting a good picture of the texture on the cards was not possible. Based on a feel of the cards with my thumb while holding the deck in my hand, the WSOP, EPT v1, and WPT cards are noticeably "grittier" than the EPT v2 and Titanium cards.
Edit: This is a closeup of the face for the EPT v2 (left) and WPT (right) cards if I zoom in on the picture above. Note that the face of the EPT v2 cards feels a bit more textured to me than the backs. I'll see if I can take a similar picture of the back of the cards.
Edit #2: pics of the texture on the back of the EPT v2 (left) and WPT (right) cards.
Not surprisingly, the EPT v2 and Titanium cards are newer stock. I suspect Fournier modified their stock in the past 1-2 years. I personally prefer the grittier cards with the brighter red, so the WSOP and WPT cards will see more table time. I didn't notice any difference in the flex when shuffling. Overall, If you prefer a less textured card, the newer EPTs may be the better card for you if you wish to try Fournier. But they may still be more textured than you like.
I left my 2826 cards and my bridge-sized WSOP cards (Bicycle branded) out of the comparison as the card size may have played a factor in feel.
Just my $0.02.