Hi Anna, the 325is is already a solid choice. I have not tried the 325e myself, but I don't think the 325e is gonna be nights and days from the 325is.
On the other hand, the 325e might have audible differences in term of sounds. I've mostly treated successors-and-predecessors as differrent buying options. It's not like the new ones are always better. Sometimes the old ones are better, but then "better" is always a matter of opinion. You may want to save a few dollars to buy a good amp/dac for the 325 (whatever the model), because they're gonna need that to reach their full potential.
Hi, and thanks for this, well guess what was about to buy 325is and the supplier dropped his price o/nite on the RS1e by $126.00 , Sooo, couldn't resist , they arrive tomorrow.