Rethinking Gryphons & Gramarye: Whitebox or Core?

One of my Sunday Game players printed out the latest draft version of Gryphons & Gramarye, read it, and sparked quite a discussion after yesterday's game. He thinks I would be better off working from the Whitebox version of S&W instead of the Core Rules version that I'm using now.

His reasons:

1. S&W Whitebox is a more basic set of rules so it would be easier to work my system changes into the system.
2. S&W Whitebox has already spun off a large number of variants. As most of them are OGL it would be easy to create a "frankengame" with the best of what others have done combined with my house rules. This would make the game more of a different game than what it is now which might make it more appealing.
3. He pointed out that we've been playing for over three years and all PCs are still under 10th level. Why go to the trouble of creating a game that can handle high level spells and characters when most old school players enjoy low and mid-level play most. Make those levels more interesting instead of trying to add higher levels than many, if not most, will never use.
4. As Whitebox is a much less complex game than Core or Complete, it lets itself to the Microlite74 "many optional rules" treatment.
5. Layout-wise, a Whitebox based game would be less trouble to create. It might even be possible to do it in 3-4 digest-sized books just like 0e.

To my surprise, most of my Sunday Game players came around to this POV after 30-40 minutes of discussion. I'm a bit reluctant due to all the work over already done, but have to admit that much of what I've done could probably be plugged directly into a Whitebox version with few changes and I am intrigued by the possibilities he mentioned.

I'm interested in more diverse opinions, however. Namely, your opinions. Which do you think would made a better Gryphons & Gramarye RPG: the current Core S&W with my house rules and few other changes version or a S&W Whitebox based version with my house rules and the best (IMHO) of other OGL Whitebox variants and, perhaps, a set of optional rules.