Yes, I do know about them. I looked at all of the Eduard sets and here are my thoughts on them:
PE flaps: They look really sharp, but the kit supplied detail looks very nice as well and I'm not going to spend 80€ on flaps, no matter how nice they look.
PE bomb bay: Not much in the set, so not really needed.
PE engines: The kit's engines look so damn nice that it is absolutely pointless to add anything to them except some wiring...
PE exterior: Same as with the bomb bay.
PE undercarriage: Looks very nice as well, but I don't feel the need to spend any more money on those areas...
PE seatbelts: No. I don't really like PE seatbelts and only use them if they are supplied in the kit (Eduard profi packs for example)
PE/fabric seatbelts: I'll definitely get those for my B-17! I really like fabric seatbelts and this set seems to have a pretty fair price.
PE cockpit: A definite yes. The interior of this kit is (like with HK's B-25) pretty nice, but the floor is lacking any structure for example. The PE set provides you with plates to glue on the floor with all the structure on. It also adds a lot more detail to all the other areas.
PE front interior: Same as with the cockpit set. I'll say "yes" to this one as well.
PE radio compartment: You basically pay 20€ for a few tiny PE bits and pre-painted plates to go on the radios. It can't be that hard to paint those radios and to be honest, the windows in that area are not even large enough to most of the added detail.
PE waist section: again, 20€ is a bit too much for that little amount of detail.
PE bomb racks: If I decide to build her with opened bomb bay doors, I'll hang some bombs on those bomb racks, so there won't be much visible of the adde detail...
Masks: They really are worth the money. Masking all thuse turrets and the rounded nose section is going to be a royal pain in the *** without them.
Brassin guns: Looks like a nice alternative to the Profimodeller barrels. The set costs about 26€ while the Profimodeller barrels are 40€. The brassin guns themselves and especially their mounts are a nice improvement over the kit parts, but the 2-part brass barrels (Profimodeller) just look way better than the resin barrels - and the barrels are the most visible part after all.
Brassin engines: Some nice stuff, but one of 4 engines sells for 25€ and the kit's engines with some added wiring look really good already, so I don't feel like getting this set at all.
Brassin wheels: Great looking wheels at a very good price. You can't really say no to this set!