Funny this comes up, spent the weekend looking at other brands, trying to make a decision as personally, I sold a fair bit of gear off earlier this year to pay nasty bills etc. Finally things are under control for the future and I can look and putting that money back into gear throughout what is left of this year. So now I have about $3000 worth of k10 and lenses (nothing special left except for the voigtlander 125). So I begin to look at do I keep the current investment, and add about $3000 in lenses over the next few months or sell it all and put $6000 into another system.
Here is my thoughts, comments are welcome
I am quite happy with k10d (I had a ds and a k100d and was just as happy, changing bodies is low priority). The d300 looks very nice, but it is a lot extra for 'nice', I also think pentax will release something between d200 and d300 in the next few months and if I bought it, it would only be for sake of having the latest and greatest (unless there is some amazing feature??). I also see the 40d / a700 as catch ups to the k10d and as fps is not an issue to me do not really see any reason to get one, the 5d has the full frame advantage and disadvantage but also that extra $1000 or so with the d300. So new body is definetly not the decider (But also not having used any other system perhaps I dont know what I am missing (there is always people say pentax has slow af, poor metering etc. but I do not know how true this is)).
So then there is the lenses
2nd hand FA* 300 - around $1000 whereas a new nikon 300mm is around $850-$950 and new canon is $1100-$1200
2nd hand 80-200 - around $1500-$2000, new nikon 70-200 vr around $1500-$1600, new nikon 80-200 $800-$900, new canon 70-200 IS $1500-$1600 non IS $1000-$1100 (+ there is the sigma 70-200 macro, which still hasn't come for pentax)
pentax 16-50 $899, tokina 16-50 $699 (personally though I'd buy the tamron 17-50* especially with how many bad ones there seems to be but not available and although rumors went around about it being released, apparently they are still denying it)
pentax 50-135 $999, tokina 50-135 $699
pentax, canon and nikon all have comparable 50-200 for around the $200 mark (nikon as vr) all have comparable 50mm primes.
anyway I could keep going, and there is obviously cases the other way (the tokina 10-17 is expensive than the pentax) , and there are lenses where there is no equivalents (ie the limiteds). But it is sad when new lenses from another system are cheaper than what we have pay for 2nd hand lenses. and of course you can just order them without hours looking through ebay and waiting for the lens you want to come along, or if you want 2nd hand the amount available is pretty amazing for nikon / canon.
also frustrating is the roadmap and delays, I now wonder about the 60-250 f4 and how much it will be, canon do a 70-200 f4 USM for under $600 but I dont think pentax will try and compete with this, they will know that even at more than double they are going to sell like crazy.
People from nikon and minolta say how great it is that they can use the old lenses too. I was thinking a little while back about getting a little sigma 24mm, for pentax they seems to be going around $100 - $150 for nikon or minolta around $40-$60.
obviously if you are into the limiteds then there is no competition but I wonder if the the difference in the cost of the body, could be made up by being able to get lenses cheaper. You lose the antishake with nikon / canon but the availability of the lenses (and sigma / tamron lenses not in pentax mount) as well as accessories (teleconvertors, macro flash for that matter the nikon flash system) is pretty unbelievable.
I still doubt if I will change brands as I am happy with the 10d and dont want to give up anitshake. But it was an interesting exercise to have a really good look at the other brands. After doing so, I do not believe anymore in the arguments of great value for money of pentax (the bodies yes, but not the lenses or as a whole system) or how great it is you can use old glass, It is great to use, I love my voigtlander but old glass seems to be available for most brands and with less cost.
anway, my thoughts, Phil