[JasonCC]

I was wondering if anyone has these and if so, has anyone worked with GR to get better parts?

[Presb4]

I have the R600's and love them. I have opened them up and taken a look. The cabinets are braced better than what I normally see, but thats not saying much. 
Im sure Danny could build a better crossover for it. But I think they would respond best if you just added around 4 sheets of Norez to start with.

[JasonCC]

Are the speakers easy to take out, I'm guessing the rings come off somehow.

[Presb4]

Not hard at all. The beauty ring just pops out from its rubber grommets. I used a small bitter knife to pry and lift them out around the edge of the speaker.

[Julian Jacques]

I was discussing this topic on YouTube with someone who owns a pair of R700's. Apperently they'd be very expensive to upgrade. I'll just quote him:
"There are a lot of parts in the R700 too. Some of the electrolytic caps have really high values (125uf, 390uf). I was going to upgrade mine but with the number of parts (7 resistors and 10 caps just on the mid/highs X 2)plus the very high values, it gets super expensive, very quickly. Caps over 5uf or so jump up big in price. There are big improvements to be had though, idk if the number of parts in the crossover will negate those improvement much or not."

[Presb4]

I think Danny just did a review of the L600's which should be a very close cousin to the R700. There's is no doubt that good parts cost $$$. Its why the OEMs cheap out on them. The polks have good bones. If the new xover parts were in the 500 dollar range with some Norez. I think it would be worth while. https://youtu.be/r6nol7rZ5cg?si=b8sp0UwdNwFwBhJq