Hey there all,
i just wanted some opinions on some higher end headphones - dont want anything too over the top but i basically had my eyes set on the AKG k701's or 601's. I guess whta i need help with is 'knowing what im looking for'. I hear these are great headphones and am planning to run them off a headphone amp of some sort in the future (when i can afford it). Just basically wanted to know how i should react to information such as this: (extracted from AKG site):

Type Open-back, dynamic headphones
Efficiency 101 dB/V
Frequency range 12 Hz to 39,5 kHz
Rated impedance 120 ohms
Max. input power 200 mW
Cable single-sided, 99.99% oxygen-free cable, 3 m (10 ft.)
Connector 1,4" hard gold plated
Net weight (without cable) 235 g (8.3 oz.)
Patent(s) Varimotion – multiple-thickness diaphragm for dynamic transducer (Patent no. AT 403.751, US 6.185.809)

basically this is all jiberish to me, and i'd like to know in the simplest terms what all these specifications mean. eg is it better to half a lower imedance rating, etc... what i should be looking out for when looking for some headphones to buy. Any help is appreciated, or if you could even direct me to a site with some info on these specs cause im lost trying to find some. Thanks in advanced.