I was talking to +James Austin about Magic in the GURPS Modern Fantasy Game. We settled on GURPS Ritual Path Magic, which can co-exist with GURPS Ritual Magic found in GURPS Magic. The decision mostly hinged on the following: GURPS Magic and Thaumaturgy which is +400 pages and GURPS Ritual Path Magic which is self enclosed and is about 52 pages.
I also considered GURPS Ritual Magic from the Basic Set p. 242 as part of our game's magic system. The over-riding idea is to bring down Data Requirements: the need to read so many books. I don't want players to read 400 books to get what I'm talking about. The plan is, we will need to take a break for Christmass and I will buy and read up in Ritual Path Magic. Since I'm already invested in GURPS Magic, I will limit it to these books.
They should have a different name for Ritual PATH magic and Ritual Magic. Like Narrative Path Magic for RPM and Core Skill Path Magic. I was reading the magic chapter and noticed the way they "tagged" the ideas were a bit messy and confusing. They used Ritual to Describe a lot of different things, where they could have just expanded the key words to better describe system mechanic elements.
I have no problem learning Tech or sci-fi stuff, since it is anchored to the real world but I hate having to learn Magic or some non-sense (like Metaphysics; 9 units worth is 9 units too much). When I learn magic rules I get shivers as it goes back to learning metaphysics and debating with sophistry. It reminds me of the lack of logic or critical thinking in my country's education system and how many bad decisions I had to go through with such a very very poor manner of evaluating and analyzing. Still I will learn it and will allow it in GURPS Modern Fantasy, I will enjoy it and make it a very good experience for the players. It is because its something a "Pro" would do.
In light of magic systems, I find the narrative systems most easy to use (which is how RPM works) and easiest to build into a story. It also follows some Economies of Action, which helps me makes sense of things and laws of consistency.