Helitech
We had a good Helitech as a first time exhibitor. There were always people on the booth or we could network around the hall. Would definitely sign up for another Excel event, probably not for Amsterdam as it obviously has no history of hosting this type of show.
When it comes down to the crunch, London has the facilities, hotels and transportation at the event location and this saves a ton of time and hassle. We too had people held up Tuesday due to fog at LCY, but that could happen anywhere. My only recommendation would be to make it a two day show, no one seemed to be thrilled about showing up on the last day and there wasn't much new foot traffic Thursday, mainly exhibitors talking to their neighbors.