There is a system I use to check out fantasy-esque systems, D&Dlikes if you will, and also D&Dlike groups. I call it the Madlin Test.
Madlin is my current D&D character. She is a teenaged Chaotic Good yuan-ti storm sorceress who is the daughter of a cartoonishly rich merchant noble. I made her to have narrative reasons to push the party-not stealing a spotlight, but grabbing one when no one else was using it, which we were having some issues with occurring. Of course a spoiled rich kid is gonna have the good idea! She knows everything. duh.
Thus, my test. If a game does not allow me to make a snake spellcaster: no dice. If a group raises an eyebrow at a good yuan-ti, or comments on storm sorc not being optimal, or suspects her access to wealth is going to be gamed upon (I usually make it more a liability then anything), then that is a good sign there's incompatibility.
I bring this up because I'm reading over Fabula Ultima tonight, and somehow, wildly, it passes the Madlin Test better then the next actual edition of D&D. Possibly better then the edition she's actually being played in. Neat.
(she's an Elementalist 3/Loremaster 1/Spiritist 1. easy stuff. the death domain cleric is Spiritist 4/Chanter 1.)