what do you want? I have a set of 2's and have heard the 2sw's. So better? the sw's have more bass, I don't care, mine are tighter with a more liquid mid, which is what i want. Could be that I have rebuilt the amps once or twice. The differences are that the sw's have a wider mouth on the lens than the 2's. And of course the 2's are full range the sw has an internal crossover (active or passive, I have seen both) the lens material on my 2's is slightly better quality than any of the sw's i have seen.
If you want to make them sound a LOT better there is a 10uf coupling cap on the small signal board, find a Black Gate non pol 10mike and change them (2). And of course your input coupling cap can be played with. Try an Audio Note copper and oil for that sweet syrupy sound.
IMHO take the crossover out completely use the input direct with a good coupling cap and get an active Xover for your subs. I use a modified Dalquest Xover. Of course you need to match the subs to the Bevs but thats half the fun.