Like you, I enjoyed my LSi 15s for about 5 years and didn't feel any real need to upgrade until recently. What I liked most about the polks was their smooth tweeter, precise imaging, and musical midrange. What I ultimately found a bit lacking was their lower end, which always seemed a bit muddy and unnatural to my ears. I also found myself looking for a pair of speakers that were a bit more resolving of low-level detail.
I auditioned a lot of speakers and wasn't able to find any that struck me as a huge improvement over the polks in the $3-4K range. There were several brands that I enjoyed in the $8K+ range but that wasn't an option for me. What I ended up with was a bit of a compromise, the Usher Be-718. The Usher's highs and midrange are really special to my ears, definitely more resolving than the LSi 15s. Even though the Ushers are two-way monitors, their lower end sounds very natural to me and they play deep enough for much of the music I enjoy. I plan to supplement them with a sub as budget allows.
Your experience may differ, of course, but since you're not in a hurry to upgrade right now i'd suggest making a list of the qualities that you most and least like about your polks and then auditioning as many candidates as you can. That's part of the fun afterall.
e
I auditioned a lot of speakers and wasn't able to find any that struck me as a huge improvement over the polks in the $3-4K range. There were several brands that I enjoyed in the $8K+ range but that wasn't an option for me. What I ended up with was a bit of a compromise, the Usher Be-718. The Usher's highs and midrange are really special to my ears, definitely more resolving than the LSi 15s. Even though the Ushers are two-way monitors, their lower end sounds very natural to me and they play deep enough for much of the music I enjoy. I plan to supplement them with a sub as budget allows.
Your experience may differ, of course, but since you're not in a hurry to upgrade right now i'd suggest making a list of the qualities that you most and least like about your polks and then auditioning as many candidates as you can. That's part of the fun afterall.
e