For legacy FT glass I own the 50mm F2, 11-22mm, 14-54mm and 70-300mm. I have now tried each of them on the E-M1. The results didn't excite me. I think my expectations were too high. These lenses definitely focus faster than on the E-M5 and the Panasonic GH2. But I guess I was hoping and expecting a lot more.
I don't think it is the camera's fault, however. I just think there are limits due to the design of the older lenses. I think, too, that I have probably become spoiled by the quiet and fast focusing of the 45, 60, 75 and even the 40-150 for mFT.
So when I tried out the FT lenses on the E-M1 I was initially quite disappointed. I wish I had my old E-520 to compare with. I even checked out prices on eBay thinking I might be able to pick up an E-520 body for $100, that I would then be able to sell it a few weeks later for the same $100. There were very few E-520 bodies available when I last looked, and for those that were up for auction, it didn't seem that $100 would be a winning bid.
After the initial disappointment with my FT lenses on the E-M1, I began to realize that these are old lenses, and that they are doing the best they can. I am now prepared to believe the several people on the Internet who feel that the focus speed of these consumer Olympus FT lenses on the E-M1 is similar to what was achieved on bodies like the E-520 and E-620 (both of which I have owned). It's just that they cannot compete with what has been produced for mFT. As I think hard on it, back to the "old" days of the E-520, I think this is correct. Then, like now, the 11-22 and 14-54 seem adequately fast for general photography, especially landscapes, but the 50 and 70-300 were annoyingly slow, and the noise of them racking in and out trying to find focus is obnoxious.
I think the 50mm F2 will soon be on my chopping block. As a macro lens, manual focusing is a fine way to go and it would avoid the noise of the autofocus, but I find the fly-by-wire manual focus ring too fiddly. Plus the autofocus is so awesome on the 45mm and 60mm macro. The 50mm just can't compete with the silent and nearly instant focusing of the 45mm and 60mm. In fact I just spent a morning with the 50mm and 60mm shooting closeup flower pictures at a local botanic garden. The 60mm was so much more pleasurable. Yes, it is F2.8 and the 50mm is F2, but I never use F2 for macros. I was shooting at F4 to F8. There were many times when the 50mm racked one way and then the other, only to stop with a complete blur of the subject. It would finally find focus, usually with little studder steps, after half-pressing the shutter a second time. Yet, in the same conditions, the 60mm locked focus easily, quickly and quietly. I like the completely internal focusing, with no lens barrel moving in and out. Very neat. And now with the new smaller focus points available on the E-M1, for macro work I think I can use autofocus all the time. The results were fantastic this morning. I didn't even need to rock back and forth. With the 60mm and smaller focus points I no longer see a need to use manual focusing for macro shooting.
[It's my understanding that the old "super high quality" (SHQ) lenses are performing very nicely on the E-M1. But their performance was always better than the consumer lenses. I am sure those who held onto these "oldy but goody" lenses are happy that they did.]