ame back from Frankfurt for 3 days of FKK bliss.  I will psst detail reports later.  
Day 1....Shark, 4 sessions
1) romanina blond girl, 8.5 on looks 9 on performance. No kissing
2) tall romanian red blond, 10 and 10, 1 hour session. (this girl i repeated 2 more times during the trip)
3)average height GND type, half italian half dont remember. 8 on looks, 8.5 on performance.  Pale skin with some meat.
4) tall romanian, 10 on body, 7 on face, 8.5 performance.
250 € plus 65€ ENTRANCE FEE
Day 2...Oase, 3 sessions
1) blond romanian, 8 on looks, 8 on lerformance.  Gave me a short blow job in the cinema on the couch, tries to upsell a lot. CIM
2) blomd tall Ukranian, 9.5 on looks, 9 on performance. Finger in my ass
3) half italian, half dont remember. 7 on looks,7 on performance. I only did it because she reminds me of my coworker.  Tries to upsell a lot abiut anal her fat ass
250€ 50€ Entrance fee
Day 3, Shark (definitly better of the two) 5 sessions.
1) really tanned and somewhat thick romanian. 8.5 looks 10 performance.  Really nice slow blow job, let me fingered her.
2) tall romanian from day 1hour session with anal., lots of kissing, made her cum by daty for hf hour, alow cowgirl, doggie anal.
3)well build portuguesse, 8 on looks, 7 on performance bjt rushed.
4)hf italian,hf spanish. Speaks perfect english. Very up front what she offers and how much. 9 on looks, hot GND 9 on performance.  Super friendly.
5) skinny girl from Greece. 9 on looks, 10 on performance. Regret didnt see her earlier.
250€ 50€ entrance fee
Day 4, my hotel room right before i leave for the airport. Tall romanian from day 1&3. 1 hour passionate fun, CIM.

Needless to say i am sad to leave, in withdrawal and wants to go back as soon as possible next year

Very nice, thanks for sharing.  I'm on my way there shortly and plan to do the same except only two days.  How did you get the Sharks girl to come see you, I was thinking of calling an agency girl for that but much better if I've tried them out first.  How did you get around?  I'm planning train and taxi instead of driving

I stayed at a hotel pretty close to shark.  Maritim kofernzhotel Darmstadt.  It was 30 minute walk to sharks.  I walked there during the day and took a cab back at nifht 10€.  The hotel is 2 min from train station to into Frankfurt main station.  When i went to Oase, i rented a car from Enterprise which is 2 minute from Shark and drove to Oase. 50€.  I asked the girl if she sees guys outside and she said yes.  I offered her 300€ for the hour to come to my hotel early in the morning and she agreed.  Of course this is after i had two sessions with her already and she already knows me.  We exchanged.info in the room after the second session and she gave me her number.  By the way, oase girls are much more pushier in upselling and shark girls are laid back.  I personally like the shark setup, while at Oase, if you sit in the room where all the girls are, you feel cery pressured.  At shark you can just sit at a couvh and watch 60 naked girls walk by wirhout any preasure to goin to a rooom.  I hope this helps.  Message me if you have any more quesions.

Just posted to say that car rental can be fairly cheap. Next week I happen to be in Frankfurt for a few days (and not with my own car). I can rent a small car for 60 euros for four days if you look around a bit. Having a car definitely makes things easier.

If you want girls to stay overnight (outcall) they will typically charge between 500 and 1000, which most guys won'y pay. Getting a phone number is very easy (if you've proven to be a good client).

Euros? That's cheap compared to Canada, it's at least twice as much here.

Looks like Shark is the place to go.
Question: I am visiting Shark on Monday (sometime next mont) - what time is best time to go? Also does the rooms get filled up fast later in the night and you have to wait?
How is the parking around Shark?
Money: Do you take cash along or use ATM in Shark?

Shark is definitely more superior than Oase, in my opinion.  I used an atm outside of the club.  The club filled up  around 5pm and emptied out around 10pm.  There are both more men and girls between that time.  I didnt experience much of a wait for rooms.  Then again, waiting for rooms are not that bad.  It gives you a chance to talk to the girl, let them flirt with you and some of them will jerk you a bit under the robe.  You get to feel them up a bit too qhile waiting.

Thank you everyone on this forum who have been so helpful, two days at FKK (Oase and Sharks) was amazing.  Both clubs has goods and bads so it comes down to personal preference.  

I went to Oase first because the scouting indicated hot, slim, young with no silicon which describes my likes.  The ladies were very friendly and most came over to chat and asked if I wanted to spend time, very business like and went away when I said no.  Said yes to four ladies, two pretty blondes and two cute brunettes.  All were in their mid twenties with great bodies, my only comment is that they had bigger breast than my preference Cs.  I'm a A-B man but I realizes that I'm a face man.  Pretty face wins the day for me over body.  All had BBBJ, LFK and CFS.  I only had CFS with one and enjoyed lots of oral fun with the others.  One of the blonde asked me what I wanted and she included BLS and licking throughout the region but stopped short of rimming.  She was amazing, just kept looking me in the eye and worked her magic.  There was lots of up-sell to go to Greece but no pressure when I declined.

Sharks had a wider variety of ladies (body and age) and I ended up spending the first couple of hours just watching and taking in the scene.  Most of the ladies waited to be approached but many did come around to check.  Sent time with four ladies also, two young hot brunettes, one late twenties blonde and a mid thirties black hair lady.  The two older ladies were spectacular, the blonde had an amazing body to boot and exactly my liking.  Easily could have spent the entire day with her but variety was the goal on this trip.  The hour was filled with games and tease, a real GFE.  The mid thirties lady was a true seductress, slow and senual with a look in her eyes that had me mesmerized.  She was my last lady and was very doubtful that she could make me cum.  She just said you want to have CIM and that's what you'll get.

I need to find a reason to return soon.