The answer to your question is that "it depends". Personally I use hyd rollers in everything I build and I recommend them for any builds that are similar to mine. My type of build is 500+ cubic inch pump gas big block with EFI. I think a hyd roller is a perfect match for a big street driver with EFI. It basically gives you a modern feel to the engine with good manners and durability. I wouldn't use a hyd roller in a race car although there are a few guys who are successful with them.