Speaker questions ProAc, Harbeth, ATC

Would like the forum's view on a potential speaker upgrade.  I listen to ProAc Response 2.5 speakers which I purchased nearly 30 years ago.  They have been wonderful.  I also have a REL T9x subwoofer.  Since the speakers are so old, I have been thinking of looking to upgrade.  The options I have on my list are new ProAcs, ATC and Harbeth.  I would be prepared to buy used.  I am looking for a similar sound to the ProAcs but maybe with a firmer bass.  I listen at reasonable levels and my tastes are classic rock and jazz.  I find the ProAcs are great with jazz.  My room is not dedicated to sound only and is 15 ft x 20 ft.  Thank you for suggestions.