I like the 1/60's but aside from lack of perfect transformation, you might want to be aware of the reduced posability relative to 1/48's, especially the arms. Drifand (a member here) has an article at Toyboxdx explaining how to modify the arms but I haven't tried it personally. The legs have a weird mechanism for swivelling (though far better than the 1/55's) which entails twisting them at the mid-calves instead of the knees as on the 1/48's.
Other quirks: personally, I find getting the chest plate to lock down correctly in battroid is very frustrating, but also not entirely necessary. Posing the battroid can be a little tricky, too, unlike the 1/48 which pretty much stands in any pose you put it in.
AFAIK Yamato stopped producing 1/60 Valks a good while ago, but the Red & Blue Queadluun Rau toys are also in 1/60 and one might reasonably speculate that if Yamato makes any destroids or battlepods, 1/60 would be a likely scale. There isn't even the hint of a rumor along these lines, though.