Again all this talk about swimming in big currents is pointless at best. Komodo is known for 8 knot currents & most websites tell you this Don't take my word for it, feel free to look for yourself. Now Guides aren't going to drop you in conditions like this but things can change underwater. Some of the best sites are pretty safe, they are just a U shaped channel where you get blown along. The sand is around 20m and there are walls either side so you only go one way. At the end of the channel the flow subsides, you hook on and watch the Mantas. It's much like a rollercoaster where it's safe but you feel out of control.
The big issue is that when divers are asked if they are okay with such sites, most say yes. It's either their ego's talking or not wanting to miss a dive. You need to be prepared to say you're not experienced with those conditions and the dive may be changed, you talked through it or in extreme cases you sit the dive out. We were on one trip where my wife and I were the only 2 who went down with the guides - as a bonus dive. The guides enjoyed being able to do that dive but it was way out of the comfort zone of the rest - they'd seen us in action on other dives. While some people were disappointed before the dive, when we came back up telling them about it they were happy not to have gone in.
Recently I was given "custody" of two new divers to the area. Both had over 1200 dives, both were advanced BSAC instructors so on paper much more experienced and qualified than I, yet they listened to me and accepted that in this case they were the novice. We had a great dive they were kind of suspect about what I was telling them it might be like pre dive but post dive they were happy to say I'd briefed them fully. So no matter how experienced you think you are, pay attention to those who dive these sites regularly.
I'd love to do a GUE fundies class. I expect if I turned up in my rig the instructor would have a hissy fit. My rig is configured to the conditions here. I have strobes, 3 x DSMB (one 12' one for the surface) An Airhorn and underwater signaling device, wing pockets, whistle, mirror etc etc. So think if you're going away what you might need. Go look at the Accidents and Incident thread to see that people are often blown away at the surface too.
@dumpsterDiver wondered why sane people throw themselves into these conditions. Fair point. My retort would be, why do people go deep into caves? At least I can see the surface, and of course the is the reward of the big fish that you wouldn't necessarily get in calmer conditions.