I ride all the SS foils and wings a lot and know them very well.
Both the H2 (new Gamma 2019 foil) and H4 (Space Skate) are higher lift foils and very stable. I'd actually give the overall nod to the H2 (Gamma) for stability. It's wider.
Both are very stable and early lift foils, but go about it differently. H2 is wider and longer and very lifty. H4 is less long, but fatter, but also very high lift.
Due to the H4 being less wide and fatter, the H4 or Space Skate is quicker from edge to edge, but both will be good for learning transitions, tacking and jibing.
If, however, you are doing touchdowns during these, these foils will want to hop back up sooner than the H5 (time code 57). Sometimes having LESS lift is easier if you are still working on your footwork and touching down. You can skim across the water faster without foiling. Having the right speed often helps in these maneuvers. Not too fast and not too slow.
If you are looking for a better foil for above the water footwork, pick the one that fits your riding style more. I think the H2 is less tippy overall.
Honestly? I like all 4 foils from SS (I think the H1 is a myth), but the H2, H3, H4 and H5 and new 2019 models are all really fun for different reasons.
Hope this helps.