Audio Research Reference 3 and BAT spec 6H30

It depends on what you consider worth doing means to you.
The 6h30dr's are much better than the ARC 6h30's, more dynamic,deeper bass,highs more extended just better in every area. But the question is are they $300 better?
Right now Bat branded 6h30dr's are going for $400-450 pr. Right? If you can afford those prices, then I guess its worth doing.
I have the Bat dr's but when I purchased them(4yrs.ago)they were $180pr.which I thought was too expensive then!
I also have a pair of the 6h30dr's(not Bat branded but same quality)that I purchased 2yrs. ago for $100 pr. They're now going for $290-$310pr.
So, again you have to make that call. If you can afford it then go for it. The plus side is 6h30dr's have a life expectancy of 10,000hrs. which if you are conservative in your playing(2000 hrs.a yr.) means they can last 5-6yrs.

77jovian, I would start with the preamp there will be a noticable difference. The LS-26 is a great preamp and deserves the DR's but eventually you will have to do the amp as well as you'll be craving what the total DR's in your system can do.