Granted Jane's F/A-18 can not compete with modern sims in the "realistic to the switch" department nor in graphics. But its AI while not perfect is quite good. Dogfighting and BVR against AI is fun and challenging. Things like terrain masking and SAM blinking are modeled.
But its real strongpoint is the campaign which is immersive and a lot of fun. It is not dynamic like in Falcon 4.0, but a well scripted branched campaign. When playing the campaign again not all will be the same, as the campaign will either dice roll or take into account the outcome of previous missions to determine which mission to spawn. For example you are tasked to mine the enemy harbor and fail, you will have to deal with an enemy task force which managed to escape the next mission.
With TSH I actually have some issues:
MDI SA Page data link is broken in some missions. Happens in campaign too, not in all missions. This issues was never fixed. I went through all the posts in the simhq forums to find that one out. This not working is a huge downside for me, as the data link is quite useful in more complex missions, even if it only shows enemy aircraft in stock.
While it offers widescreen resolutions at least on my machine I am getting rendering issues with those and I am stuck with 1024x768 like in the stock game.
Some rendering issues with some bomb craters. A hole square of tile is either black or flickering.
As stock just runs fine on my machine I settled for various high-res mods to make it look better. For example the "Terra North Cape" terrain mod by blitz looks even better, at least for me, than the TSH landpals. However one thing I use from TSH mod, that is the high-res cockpit. Which is really nice and a real improvement of the experience. As for the aircraft and weapons skins, most of these are available for stock too.
Funny you mention that name. Not only was Matt Wagner on the team, he even created the Valhalla campaign, the first campaign other than stock for JF18. His campaign is IMHO even better than the stock one.
The TSH and a whole lot of different mods can be found here:
https://www.jf18-resource.com/
As for missions and campaigns the owner of the site mentioned above has it uploaded on his google drive as mentioned in this reddit post: (don't want to post a direct link to it as it is not mine.)
https://www.reddit.com/r/hoggit/comments/184q3o5/comment/kazqhfh/