Brimar vs Mullard cv4003/12AU7

I’ve used both as input tube and drivers in my power amp. I very much like the combination.
The Brimar has warmth with more depth and more extension at both ends. Tight bass. Mullard has the warmth but is more refined, realistic with soft highs. A Mullard in the right circuit can sound holographic.

I purchased my Brimars from Upscale after trading emails with them to get a thorough description of their sonics. They came in original NOS boxes with plastic pin protectors and are well built tubes.
There are at least 4 different types of Mullards with a different sonic signature, the cv4003 is the ruggedized version. Sweet, liquid mids like the Brimar, both have boxplates.

@bradbort , yes it's system dependent. I'll add that it's component dependent.
I used Mullard longplate square getters from the 1950's for years in a preamp. Also used a Mullard CV4004 as an input tube in my amp.
When I changed to a new amp, I needed more clarity and extension, and the Brimars were a better fit.