i,m a brickie by trade, but i did literally 1000 sq mtrs during the 90,s when the Berlin wall came down. ( bus stations , lorry parks etc ) and i agree its all about the prep. wacker plate heavier the better a good tip is stand on the finished screed - you should not leave a footprint , also wet sand is no good.
The weight of the wacker has no bearing on it at all (a very common myth), its actually based on the impact force per m2. Hence a smaller plate compactor with a small base can have a much higher impact force then a larger item with a big plate. In this case, the smaller one will give greater compaction and give better results.

(Studied this in great details before purchasing one

)
My finished base took the weight of the rear wheels of a tipper which was dropping another 10 tons of base!

(Which I was pretty surprised by)