TE2 HIPS kits are about 2 mm or 0.08 gauge, the same as AP if I recall correctly. The thing with HIPS is that it contains less rubber than ABS, and keeps it's form better when cooling down, compared to ABS that likes to "flex" back a little when cooling, requiring a more constant vacuum to keep it's desired shape after it's been pulled over the mould. This means that HIPS is easier to pull with high detail since it doesn't flex back as much, whereas ABS requires more skill and better equipment to retain sharpness. At least that's what I've read.