I’ve done it, went on a week day in mid December. Well worth a visit, very informative & loads of surprising stuff. The tour itself takes around 90 mins, then there is the museum part, a really cool cafe, with decent grub & then a well stocked merchandise/clothing shop .
My lad bought me a vin plate key ring, aswell which is pretty cool. You have to pre-order them online so they can make them ready for your visit day, but it is basically my bikes vin number on a proper alloy vin plate with reg as well etc. Was a nice early Xmas prezzy