Harbeth Super HL 5 Plus room size?

Would this Harbeth be too big for my 20x15x8 listening room. I sit about 7 feet from my current Harbeth P3 ESR with JL Audio subwoofer. There is a pair listed here at a good price. I love the sound of the P3 in my room and was wondering if the larger ported Harbeth would be the right move to make? Are there any HL5 owners out there? BTW, a few years ago I tried the Compact 7 and I preferred the smaller P3!