Nicholas Meyer did a fantastic job with Wrath Of Kahn considering they had little to no budget. He also had a wonderful and paced perfectly script. I thought he did a good job with Undiscovered Country, although I didn't think the story was as strong as Wrath of Kahn. Jonathan Frakes was great with First Contact and give the subpar script for Insurrection, I think he did the best he could with it.
I agree with both your points, especially about Frakes. I think Nemesis would have been much better if Frakes had directed.