I have many engines, and I have even bought engines after I had Leadwerks (for special needs, like shadows on Android, which not even Unity3D can do), but Leadwerks is very different than other engines. Leadwerks is completely free of any restrictions in game and art design, while most other engines are usually limited with a too heavy GUI. Also the last engine I bought has that problem. You can't do freely what you want, but you have to follow the restrictions of the engine design, although the engine itself could probably be able to do what you want, but the engine GUI is what it is, limited. And when you try to program freely, you encounter lots of bugs in those other engines, because they are not tested and designed to be used freely.
Exceptional in Leadwerks engine is also that the freedom of game design does not cause more difficulty in programming. That is so, because Leadwerks was developed after the syntax of the super easy Blitz3D engine, which still amazes me today (I played a little game which someone made in Blitz3D today, very short and simple code), but unfortunately it is very outdated, and supports only DirectX 7. Now the new upcoming Leadwerks 3.0 has a new feature, which allows it to act like Blitz3D 2.0, a very low-end capable engine, which works on every toaster and even Intel GMA chips.
One of the biggest reasons why I never stop using Leadwerks, is the community. It's a very friendly and creative community, and everyone is offering free tools, tutorials, assets and code for everyone. No other engine community I've seen has done that. Everyone is someone in this community.
Artists are rare and very well served in this community also. If you need some code example, you get it guaranteed almost immediately and for free, especially if you offer to do some little 3D model as thanks But many would also accept money if you need contracted support, even Josh. Or especially him, and other people should not take that opportunity unless Josh is too busy with other things