At first I couldn't play Crusader 2 because of weaker hardware, but later I also came to the same conclusion, it's not that interesting. However, I wouldn't say it's anything like Stronghold 2. If it is anything like that, it is a watered down Stronghold 2. It is a 3D game, but everything is oversimplified.
And one important thing about Crusader 2 on PC's with low specs. In low settings you cannot see fire, you cannot see that you're troops are burning. That's frustrating.
No moats, no laddermen, no siege towers... All that makes fighting in Crusader 2 less exciting. You just need to make an army in huge numbers, and storm your enemy, while we all know that simply doesn't work in Crusader 1, or Stronghold 1 for example. That's what makes those games exciting for me. Once you're way stronger, and at one point your opponent has destroyed your entire invading army, and the war has been turned. This can happen in Stronghold 2 as well, though it's less likely.
And for gods sake, it's 2018, and we still don't have a Stronghold game with unit collision. This has been a thing in games of early 2000's, and Stronghold still doesn't have it. It would make field battles much more exciting, and sieges as well.
Regarding Stronghold Next. We shall see, but the interesting part for me now is that they definitely plan to bring something different, it's not going to be 12th century England, nor Crusades. It seams it's going to be something else.