Do we really need anything more than 8" woofer and 1" tweeter for medium size room?

Need more than an 8" woofer?  Yes.

Get a large,sealed subwoofer and see just how much DEEP BASS you are actually missing in your music. My main Tekton speakers (Lore Impulse) are using pretty cheap 10" Eminence paper woofers and these speakers play LOW (and I mean LOW) already, but the REL G1 is generating bass tones and articulation below 20hz that I have never even heard before.

I cannot imagine (unless you have a very small room) that a pair of 8" woofers (in a speaker - not a dedicated subwoofer) will be anywhere near enough bass to really create a full range sound.  If you have a large 2-way bookshelf or even floorstander with 8" mid-woofers in them, there is no way that they will be hitting down to 25hz or lower in your room.  Even adding a dedicated powered 8" subwoofer (or a pair) will still not carry you down to the very low frequencies.  Now you may not listen to the types of music that even contain these frequencies, which is a different thing, but when you listen to some of the music that I do, there is A LOT happening down low that I never even knew was there until I bought a subwoofer like the G1.  Simple physics... if you want to reach really deep and have control at the same time, you really need a large sealed box, large woofer, and pretty decent amount of power.  And an 8" Sunfire subwoofer.... ummmm, no.

8" woofers (or subwoofers), no matter the design, are never going to dig deep enough for the types of music that I listen to and as loud as I sometimes like to listen.

@bassdude

I'm sure it sounds great, but not nearly what it could sound like with a full range pair of speakers and/or a powered subwoofer.  I guess it kinda depends on the types of music that you listen to.

Again, I think it depends on the type of music you normally listen to.  If you came over and sat in front of my system with the Tektons and REL G1 and I played you some Muse and Volbeat at loud levels, then you transport back to your system with what you think is "full range" sound and listen to the same tracks, it wouldn't even be close to the same experience... just not possible.  But that type of music may not be your cup of tea either, which I understand.

If I always only listened to Norah Jones, Mary Black, James Taylor, Michael Buble, etc., then my system would be totally different.