Best speakers for $1500 or less?

You haven't really specified what it is you like so much about the 1.5s or what's important to you from a sound reproduction standpoint so tough to make specific recommendations. I demoed the 2.5s in my system so I probably have a good idea of what the 1.5s sound like sans some bass. But just for some others worth consideration...

The Silverline Preludes are certainly a popular option in that price range, and I'll throw in Golden Ear and Epos as well that would be worth a listen. If you have a Nola dealer nearby the Boxer would also be a great speaker to hear. There's a pair of Joseph Audio RM25si Signatures for sale that you might be able to negotiate down close to $1500 -- imo they would blow the 2.5s out of the water let alone the 1.5s. There's also a pair of Reference 3A Decapos for sale in this price range as well, and I'd take those way before the 1.5s as well. But then again it all comes down to personal preferences, and if the 1.5s really do it for you that's what matters most. Hope this helps and best of luck.

Another speaker to look at is the KEF LS50 Anniversary. Recently did a demo and the sound was impressive. If I decide to downsize my Media Room system (which doesn't have the real estate to support Maggies or Martin Logan's)I would likely pull the trigger on these. (For the curious, I'm running B&W 805Ds through an Ayre AX-7e)

If you have slightly more budget, B&W CM8s have a great sound, are floor standers that can fit within a narrow space, and have a great fit & finish for the money. Hope this helps.

I recently listened to Spendor and Dynaudio. Don't forget about Spendor, very nice speaker. I have the small S3/5 in small 11 X 12 space, and they are excellent. The one I heard at the store was a 3/1 R2, just a little bigger than mine. Very nice indeed, but may be pushing your price range if buying NEW.

Try to give the Spendor 3/5R2 a listen. They are in your price range. I had the 3/5's years ago and thought they were a great little speaker!

I would consider A pair of Pre owned Vandersteen 2CE Sig 2s they may catch you with their out of the box lower profile baffle less enclosure which is most likely what you like about small mini monitors.
Yet they will dig deeper into the bass offer a smoother more enjoyable in room response
add to that they are phase and time correct, Made in USA with great coaching on setup, support etc.
Vandy dealer for over 20 years.
JohnnyR