The thing with a Sheffield stand is that if I have an errand to do, have taken the recycling on the way etc. and have my trailer attached, I can lock the trailer to the bike and the bike to the stand. I imagine recumbents, trikes and other HPVs are better catered for with a Sheffield stand (assuming room enough to access it). I often arrive somewhere with panniers laden already, before shopping to cram even more weight on the bike - I can run a cable lock through the pannier handles if I can't take the panniers off - I don't want to have to lift a bike.
Other designs which are more "tailored" become more exclusive to a standard unladen bik, and I wouldn't particularly like shelling out good money for a recumbent bike, start a job at a new company that boasted about its wonderful facilities and then find that my bike was "the wrong shape" for the cycle parking facilities there.
Not to say that the newer designs don't have certain advantages, however many seem to assume that any HPV is a rougly standard shape and doesn't have any luggage or other attachment. I'd like to see designers start with a laden recumbent trike with trailer as an example of the vehicle, and then make it also suitable for a lightweight road bike with no rack or guards.
If I were speccing cycle parking, purely as an ideal, for somewhere with a limited space, I might look at the cyclepods to get more capacity, but I would still add a number of Sheffield stands. I'd bet the Sheffield stands filled up first - although admittedly maybe just from riders' habits.