Want to upgrade my speakers ... input please ...

Hi,
I want to upgrade speakers from my dahlquist 20's to either the Thiel 3.6 or the Alon / nola II plus or possibly to the Vandersteen 3a's my question : Looking for input on the best direction to head off into on my quest to upgrade speakers .... I havn't heard the above mentioned speakers, just going off feedback and reviews .. any input is appreciated .. Thanks in advance !

Mcintosh 2500 for power.


Warmest regards,
Ron Larsen ..
ronzolarsen@hotmail.com