Right, having only found vague remarks/reviews online I thought I'd go and check them both out.
For the TL;DR version - avoid Caligula, King George was fun.
Tried Caligula first. 99 euro entrance became 100 when I actually turned up. Sternly warned no refund if you go in and don't like what you see. Should have realised what that meant. Anyway, 5 or 6 mostly Romanian whores standing around looking bored, texting their mates, chatting with each other, completely ignoring the customers for the most part. The club itself whiffs a bit of horny men, unsurprisingly. Separate smoking lounge. Over the next few hours I just made the best of it, shagged as many of the disinterested and not fabulously attractive women. Most tried hard upselling - 10E for blowjob with no condom, 10 for kissing, 25 for anal. Whenever I said no they'd get pissed off and result in a totally mechanical fuck you as fast they can to get rid of you session. One girl who was not like that - but whose name I cannot remember (lots of whisky... might have been Tanja) didn't try any upselling and with her I had three nice sessions including getting her so relaxed with a bit of oral and massage (on her) that she was close to drifting off into a snooze. I.e., she was knackered. Long hours, and the popular girls (which she was one of) don't want to leave when they're still busy. Anyway apart from that one lovely lass, the rest were pretty forgettable or actively shite. I would not return.
King George the next night. 99E fee, handed over 100, got my 1E change - yippee! Told there were 7 girls on, actually turned into 9. Smoky smelling club, smaller than Caligula but rooms much bigger and toilets a lot cleaner. It was dead when I arrived at 5PM and half the girls were the hard faced Romanian types, doing the ignoring you and fiddling with phone routine... and smoking too - oh oh. Thought I'd just fuck a few and leave to not waste an entire night again. However when a few more guys turned up the girls sprang to life a bit more and by 8PM some of them were dancing with flashes of cunt and tits, I had been thoroughly fucked by 3 of them with NO upselling AT ALL and from then on it was just a pleasurable mixture of drinking/resting and then picking another bird to bounce on. Ones that I can remember were:
Miriam who 69ed like a tiger and enjoyed having her ass eaten so much she spent some minutes sitting on my face
Katja who was incredibly short, lots of fun and who came - a lot - and clearly approved as she dragged me off twice more for repeat sessions, I was even sucking her tits at the bar at one point.
Ramona - bigger girl with huge tits, a mild attempt at upsell but not bothered when I said no and still shagged me nicely
Klaudia - MILF type but boring as fuck both in terms of boring you to death with talking and being a dead fish shag
...and there were others but forget the names. I avoided the hard faced looking Romanian ones. There was an annoying ugly black women sat talking to the barmaid, and both of them were rude and irritating in their manner e.g. shouting at customers for laughing too loudly. Well fuck me for having a good time, cunts... anyway didn't let it ruin the evening and staggered out at closing time fully satisfied.