Have heard them both ... they both are excellent. However, I’d go with the 53se over the 43se because the 43se, being solid state, sounds a bit "dryer" to me than the tube-based 53se. Quite frankly, I would go with a VK-33 or an older VK-3i since they use 6922 tubes which you can roll to modify the sound to your taste. With the 53se, you’re stuck with the 6H30 supertube which, IMO, sounds a bit thin.