300B SET or EL34 SET

I've never owned a 300b amp because of the cost of the tubes. I have an El 34 amp, and tube rolling won't break my bank! But really I think that its all about the design of the amp that makes the biggest difference. Some 300B amps will outdo a El34 amp in the areas that your asking about and some EL34 amps will outdo a 300B in those same areas, depends on the design.   Do you have some amps in mind? If so someone who owns one might be able to answer better.
Good Luck, TISH

I'm thinking of Audion Sterling EL34 and Audion Silver Night (300B). I tought my Tannoy Legacy Eaton at 89dB sensivity would be too hard for the 300B amp to drive but Graeme at Audion says it will be no problem.

Both tubes (EL34 & 300B) have a pronounced midrange profile but IMO (based on the amps I sell from Art Audio) is that the EL34 has a pronounced mid emphasis and the high's are a bit rolled off compared to say, a KT88.  The 300B has a lush, almost addictive midrange with excellent high frequency extension.  

Bass response will never be as good as with a solid state amp but ultimate bass response will be driven by the quality of  the output transformers.  

89dB is low for a 300B.  Whether it is adequate very much depends on your room.  In a smallish room with speakers near the corners, yes.  In a larger room.