Dims on my 5'2 are 5'2 x 19 x 2 5/16 carrying about 29 litres. I am 5'9 and 90 kegs, so that's a pretty small board for me. For comparison if I were to be riding a regular HPSB it would probably look something like 6'1 x 19 x 2 1/2 around 30-31 litres.
with how straight the outline is and how much surface area the design has, I think going longer is just defeating the purpose of the design. I don't think it's so much about going a little under volume, more just having a similar volume come out of smaller dimensions. eg the 5'2 is only 5/16 thick, but the foam goes all the way out to the rails and is foiled pretty thickly to the tail to give me a similar volume to a hpsb. gotta remember you still have to paddle the thing.
As for 95% of east coast waves, maybe a bit less the downfalls i am finding are:
- tiny gutless waves - you can surf it but it;s hard work like a HPSB, better off on a full on groveller imo
- sucky reefs - a bit more paddle power and rail to get in earlier is more comfortable. It's fun once you're on the waves though
- choppy conditions - it is a little more sensitive to chop than more regular boards.
I've got a 5'3 1/2 x 18 1/2 x 2 3/8 carrying a bit more volume and a little less concave that i've finished now and only surfed once, with more of a rounded tail. Only had one surf so far and it was in 4-6ft backhand sucky point break waves, so a bit hard to judge, but it felt good so far.