TLDR: Never deal with the devil.
I felt like the weakest part was Olgierd's third task, the game was essentially a walking simulator, you knew the wife was dead and that you would have to pull off some ghosty/time-travelly miracle to get the rose. The Caretaker was a nice touch, but is never explored further, much like Olgierd's dabbling in the arcane arts and the photoshop filter was a bore. I hated the part where the game drops you into a blizzard and you can't see where you are going if you have used Cat, felt so cheap.
On the other hand, the wedding and the robbery were pretty fun, easily one of the best quests in the game. Wedding was nice with all the upbeat atmosphere without the grimdark stuff the witcher universe is full of. They pulled off the celebratory mood really well and Vlodimir's lines were awesome. I will have to read up on how the people you hire for the robbery affect the quest, I had the elf and the safecracker. She ran away through the chimney in the middle and the safecracker joined the auctioneer's side only to lie in a puddle of blood 10 seconds later...
I let O'Dimm take Olgierd's soul because honestly, the guy was a dick and you don't piss into the devil's coffee. Then didn't accept anything in return just to get the fuck away.