Originally posted by wowtip Do you know if the 64 is going to replace the 58, or if they will coexist?
It's probable that the 64 will officially replace the 58, but it's also likely that for quite some time both will be available. After all with some retailers it's still possible to find a 50 even though the 52 has been out for a few years.
Originally posted by Kerrowdown I always go for the most power, you can always turn it down a bit... but doesn't work the other way.
Keep in mind that the 64 only has this guide number at 200mm. I'm willing to be that it's not really more powerful than the 58 at 105mm.