Is this the best analog has to offer?

As I have mentioned in these forums, I recently made a serious return to vinyl with a Michell Gyro, OL Silver arm, Shelter 501 cartridge and Sonic Frontiers SFP Signature phono stage and the purchase of every new jazz records from the 50's- 60's that I could still find around ( a few hundred)

I've been listening to this setup for a couple of months now with around 50 hours of burn -in on the components and while direct A/B comparisions of the same material on CD to LP lead me to the conclusion that LP is better, it is not as significant a difference as I had expected.

I'm wondering whether I still have some things to further adjust or whether there is a weak point in my system. I purchased the HIFI NEWS test record and have tweaked the cartridge adjustments as much as I think is humanly possible. The biggest complaint I have about the sound of the LP's is that they are rather "dry" "zippy" and "buzzy". Brass instruments sound more "plastic" than metal (Maybe this is the sound of the vinyl?) I know I'm not using the best audiophile terms to describe sound but it is how it sounds to me. This is not true on all records. Some are far beter than others.

On the other hand I can definitely say the LP's do have more detail and sound stage than the identical material on CD. The LP's are so much more detailed that I hear flaws in the master tapes that I never realized were there from the CD. I suspect that my disatisfactions with LP sound are really the inadequacies of recordings from this period that are masked by CD's and not flaws in the LP. The fact that some LP's are far better than others also suggests to me that the difference in original recording quality is more important final recording than medium but I'm not sure.

I would also comment that in my opinion a well recorded jazz CD made in 2003 sounds far better than an average LP recorded in the 50's or 60's. Of course, I suspect a well recorded LP from 2003 would sound the best of all but since hardly any exist it is a moot point.

Any suggestions on what to try would be appreciated!