Standards and Kings both tend to much more even than Kays,now there are exceptions to any,Ive seen some dang good Kays,,and some bad sounding Standards I think the best Kays Ive ever played were pre war 36-39,,that goes for Kings and Standards as well, As more Standards surface I hear some that are almost too big and hollow sounding,they lack note definition .Just because they sound big and loud dosent mean they are all that good, but It does depend on what you use it for, I still have my old Standard that I used on the road, I mainly use if on bluegrass gigs where I'm going to mic or play loud with out a amp ,It cuts a mic like no other , but for recording it's not that great .Ive had a number of conversations with audio engineers about what they like /dislike about recording upright basses, and just about all of them say the unevenness of most plywoods is the worst thing they have to fight, another thing I think really hurts recording or just using a mic on a upright these days is the over use of compression. I think it is used sometimes to help balance out the unevenness the bass may produce, in return it just takes the soul from the instrument. I recently heard some newer bluegrass band on XM, and the bass was so compressed you couldn't hear the tone of the note. I did some research and found the player was playing a Standard , again I think the set up and strings also make the difference. I do belive a lot of bluegrass players sell themselves short by not buying a decent bass,, and not getting a good setup,but on the other hand Ive watch Travis Lewis a million times back in the day playing the Lewis familys old beat up Kay with 40yr old Supernyls on it and sounding like Bob Moore. A good bass can produce a much richer almost 2 dimensional sound when set up right and recorded/mixed right but it also comes down to the man pulling the strings. Back to the King/Standard bass, they are somewhat a challenge with the longer scale ,and if you switch basses it will mess with you .I have 3 basses I play One Standard with the 43"scale,one German carved bass with a 40" scale and a Eb neck, and then a German with a 41" scale and a D neck,,that will mess with me if I don't get which ever bass out and play it for a few days before I gig/record with it.