Its not too bad at all.
There are some IQ tweaks to make the game look better. I only ran though about 4/5 of the maps. But those were not too bad at all. I am a fair Helo pilot in both DC/EOD so playing around with the Helos here was not too big of a deal. I am sure Die Hard Helo fans from DC/EOD will complian but I liked the changed. Much easier to however and you have gauge that gives your pitch/roll which helps a lot. To me it does not feell like a mod but a tweaked version of the game. Yeap lots of fun here...