I'd appreciate an idea of what the new Mongoose version brings to the table.
IMO, the strongest point of MRQ2 is it's an improvement over RQ3 from a rules standpoint- not nearly as fiddly/more streamlined while still offering alot of the flexibility in magic, combat and character options-probably what many people hoped RQ3 would have been (including myself)
Given the quote in your signature, I doubt this is a barrier, but you should be aware that the MRQ II rules are definitely written with a "spirit of the rules" intent. There are several sections where the rules are deliberately ambiguous, and the correct interpretation of how they work is, "how do you want it to work?" I'm not sure if this was true of MRQ I, as I don't have it.
If something doesn't quite click, it is definitely worth going over to the Mongoose forums and reading through some of the topics.
Compared to previous versions of Runequest, the latest version has sorcery that is easier for a character to start, but not as powerful for an accomplished character. This could make converting some spells from older sources a bit dicey. OTOH, the new spirit rules are simply cruel to any character without the appropriate counters--by design.
Did you get "Empires" in the bundle? That's got an interesting approach to running estates/countries.
Which version of Ruenquest, and which magic system, did you find confusing? Some types are more complex than others.
If you mean as far as Glorantha? Eh...not much, IMO. I'm not a fan of the 2nd age of Glorantha as MRQ has been using. One of the real attractions for me in Glorantha is the Lunar Empire, and the "stage as set" during the Chaosium and later AH days (also Chaoisum, but I digress). Not to mention the writing quality is much better in those Chaosium/AH Glorantha products. 2nd age kinda feels like the "prequels" for Star Wars- you already know whats gonna happen, and the plots/characters are lame. The new Glorantha 2nd Age book for MRQ2 is however much better as a resource than the MRQ1 version which is disjointed, difficult to read and utilize. They totally overhauled it from a utility standpoint.
I also read through pieces/parts of the Glorantha setting book.
This is my first time really ever reading about Glorantha's "history" and I have to say it is still very unique to this day with its basic rule of "Our laws are based on magic, not physics." I think the world of "Oathbound" is the only other world I have read where similar rules apply.
Which is cool, because as a GM you can pretty much have anything happen and you can say, "Its that way because some god decided they wanted it that way back in the "X" Age."
So if for some reason you want a river flowing up a hill or mountain, it can have happened in Glorantha.
I also like that it has a Blue Moon, which is a god, and is very hard to ever see at night except at a specific time, and I think it is even a place. Don't remember. I was reading for feel, not rules retention.