Sealed vs ported plus room setup acoustics probably hold the key. The manufacturer can help you with room/speaker setup and ported vs sealed expectation.
For me, subwoofer setup was in itself instructive, because I wanted bass without noticing the addition, except when doing an A/B. If I were use to booming, less tight bass my requirements might have differed. Also, integration of subwoofers is likely easier with your floor standing speakers vs smaller speakers. I realize that exceptions exist, so you do have the option to add subs in the future. My speakers have a 3dB down point similar to your speakers and my RELs were easy to integrate once I treated the room.