Upgrade from Silverline 11

I have:
NAD 320bee(50wpc) ,10x15 room, rock-blues-jazz;
solid bass, detailed high, open sound stage. $1500-17 aprox..

As I said I like my used Silverlines I wonder if I can refine or move up. Thank you.

All good points and advice. I'm alittle afraid of overwhelming the room (small) flr sprs. thus the monitors.
This is all quite helpful. Cheers!

PS: I've been offered Silverline 17's from Audiogon member that lacks references (rating). It could be alot of money to lose. Thanks.

I will check out the Merlins and hold out as I have for some 17' or 17.5's to appear also. In the meantime I will listen to the Silverline 11's and my Tyler talo mini's.
Keep the tips coming, everyone's input is very useful to the novice I am. Thanks.