I have used this technique both on wet fly and waking or skating patterns for summer steelhead on Vancouver Island and on some of the larger river systems that hold summer fish in both the USA and Canada, notably the Clearwater in Idaho and the Thompson and Skeena river tributaries in BC. The upside is that under the right conditions this method can be very attractive to the fish and can trigger very agressive responses, I had one fish on the Clearwater come to a riffled hitched wet fly that really sticks in my mind, this particular fish totally cleared the water and took the fly on the way down, the only steelhead adult that has ever done this to me although I have seen this response more often from steelhead pre migrants.
The downside for me at least is that the hooking and landing of fish using this method is very uncertain, whether this is a result of the angle of the hook from the leader when hitched or the style of the hook used I am not sure. However for this reason I now generally use a fly designed for creating a wake without the use of hitch when I fish on top. Hope this helps.