How Important is Sound? Really?

[andytoh]

I have a related question. My 7.1 surround audio system cost me about $6000 Canadian:
Yamaha HTR-6090 receiver
2 Polk RTi10 tower speakers
Polk CSi5 center speaker
2 Polk RTi6 surround speakers
2 Polk FXi3 back surround speakers
Polk PSW125 12" subwoofer
Monster Powersource HTPS 7000 MKII power conditioner
Monster TXH HP cables.

I bought the best Polk speaker models that were available in my Futureshop. My question is: exactly what specs makes one model better than another? Let's compare the specs of my $1400 Polk RTi10 tower speakers to the $1000 Polk RTi8 tower speakers:

RTi10 ($1400):
Crossover Point No
Frequency Response 20Hz - 27KHz
Magnetically Shielded Yes
Mid Range Speaker Size 6 1/2"
Power Capability 300 Watts
Product Dimensions 19.7(W) x 110.8(H) x 44.5(D) cm
Product Weight 29.9 kg
Sensitivity 89 dB
Tweeter Size 1"
Woofer Size 7"

RTi8 ($1000):
Crossover Point 2.2kHz
Frequency Response 30Hz - 27kHz
Magnetically Shielded Yes
Mid Range Speaker Size Not Applicable
Power Capability 250 Watts
Product Dimensions 19.7(W) x 105.7(H) x 39.4(D) cm
Product Weight 24.9 kg
Sensitivity 90 dB
Tweeter Size 1"
Woofer Size 6.5"

So trying to answer ReduxInflux's question QUANTITATIVELY, the answer would be that better sound means:
higher power capability
greater speaker size (i.e. tweeter and woofer)
greater speaker mass
greater frequency response range

I'm just going by the specs. Is it that simple?