Subject of much debate. Some people say it's worth the effort, some people say it's cheaper and easier to just swap the h23 for an h22. Search the forums....here's a link to one thread:
http://www.automotiveforums.com/t324703.html
...there's a bunch of threads about it so keep searching...
H22's have a 10.6:1 compression ratio - and I think the Type S head brings the ratio up to 11.0:1, not the pistons...so you might want to research that before you buy some high compression pistons.