Yeah, OK, but none of the saws I routinely use have slow throttle response (or I wouldn't use them....). That's why they're all ported at least muffler modded. It's not like I'm getting bored waiting for them to spool up, and I've never felt like it was so slow it put me at risk. So if the injection system makes it snappier, it can't be by all that much.
To be honest keeping up in the back cut seems more like an issue of cut speed after the rpms get up - does it have the power to keep up the rpms while the chain is (hopefully) biting well?