Room size for Proac Response 3.8

I'm looking into getting a pair of Proac 3.8. Those with good results what room size are you using them with? My room is 17x17 with 8.5 foot ceilings. There's a good amount of furniture, rugs, and curtains. I listen near field and usually at moderate levels. I used to have a pair of 2.5's and had good results but was forced to sell those. I am now wondering if my room has enough space for a pair of 3.8's to breath. I do not want any bass overload or boominess. The 2.5 had good bass in my room but I want more extension without adding a sub. And other than better bass, what advantage does the 3.8 have over the 2.5? Currently I have no speakers but love the Proac sound of the older series. The D25 and D38 both lose a bit of the honey in the midrange, although the resolve detail better.