I own this game quite a while, occasionally taking free flights in Seattle and i must admit - level of detail in envelopment is far beyond for any flight simulator game even today. There is probably thousand of different models for buildings, not only for landmark, but any major building have it's own model and detailed texturing. Those also all collision enabled, meaning you can crash or land on. Even trees are crashable 3D models. You can even land and get out of your bird and start playing ARMAII in Seattle. Or in normal ARMAII maps - if you own it in Steam.
I was so looking forward to start playing single player campaign, imagining limitless country of fun with all goodness above combining with full range of civil helicopter's activities, starting with simple taxi missions and ending with sling load operation and search-and-rescue mission using FLIR (thermal vision camera).
To my very disappointment there is - as we russians say - one spoon of ♥♥♥♥ in barrel of honey. And it's flying itself. I'm not IRL pilot so i can't explain things in the right worlds, but i own (and fly almost daily) DCS UH-1 and X-Plane 10 with some payware helos, so i guess i know that is right and that is wrong. And TKOH helicopters are behaves wrong. More of that - they all share same dynamics, just with different coefficients. For example all of them have same speed. It's not like i didn't notice that playing free flights, i just thought i could deal with slow response, overreacting titling and nonexistent transition on lightest bird in campaign.
Turns out what with adding more power by coefficients thing only becomes worse, so heaviest copter not only overreacting inputs (but still slow) but tends to get lift with smallest lateral movement and suddenly drop it then you manage to get steady. Combined with oversaturated (remember - we have add power) tendency for forward movement (you need a several degrees of back pitch to hold it in place) makes most docile and presumable easy to hover craft unmanageable. So on second container in 7th mission of campaign i ragequit.
Speaking of campaign - in 7 (+2 sidemissions) missions i did, there was only two civilian missions. Three if you count whale seeing mission, but single engine helo without emergency water landing equipment not sounds like civilian job for me here. And there is more of such nonsense. Why two-engine helicopters goes down after one failed? Yeah we have two turbine for fancier look. Why we need rope insertion on flat roof in heavy wind, especially after i perfectly landed before mission marker even appears.
Concluding, i wouldn't recommend this game to any flight sim enthusiast. Despite perfect envelopment flying itself is unbearably broken and won't be fixed because of 3rd party component BI have to rely here.