Originally posted by rparmar I am a big proponent of small and light gear. But even I have never found a photographic situation when a 130g difference mattered.
Many of Pentax's DA lenses are actually fairly usable on 35mm -- most of the primes longer than 40mm. The big benefit seems to be in the zoom department, where you can get relatively smaller lenses to get the same angle of view.
As far as a difference, it does make a difference. A K7 with a DA 40 or DA 35 on it will slip into a hand bag and go anywhere, whereas a D700 with a 14 to 24 f2.8 zoom is going to be tougher to "slip into" luggage.
I agree, if you are shooting professionally, it doesn't make a difference. In fact, clients are more likely to be impressed by huge lenses. But, even professional photographers like smaller gear when they are on holiday.