Sorry. Yes. In terms of exposure, it's still an f/2.0 lens (which is good!) In terms of Depth of field, it acts like a 100/4 lens. DOF is determined by distance to subject (for the same framing, that's driven by Focal Length. The longer the focal length, the farther back you have to stand. So a 50mm lens on a 2X crop body means you have to stand back the same distance as if you had a 100mm lens on a full frame body).
The other factor to DOF is aperture (aperture as in the size of the opening, not as in f/stop. So, a 50mm f2.0 lens opens at it's widest to 50/2=25mm. A 100mm 4.0 lens also opens to 25mm).
So, in terms of field of view (and therefore distance to subject and the same framing) and DOF, 50mm 2.0 lens on an m43 camera is equivalent to a 100mm 4.0 lens on full frame (or a 62.5mm f/2.5 on a 1.6 crop). But, the exposure would be as if 2.0.
A 50mm 1.4 lens acts like 100mm 2.8, which is nice since these legacy lenses are only like $30-60 on ebay (and another $30 for a given adapter)! But for various reasons, most 50 1.4 lenses look soft on m43, so they need to be stopped down to 2.0. The 50mm 2.0 macro is sharp at 2.0.
Manual Focus is also MUUUUCH easier on m43 because of the LCD and MF assist, with real live view (no mirror flip down/up). So, it's a lot of fun. But, it's still not going to replace sports shooting on a DSLR by any stretch! (and to get the equivalent DOF of a 50mm 1.8 lens on a Canon 5D, you'd need a 25mm .9 lens for your m43 camera -- not going to happen!) So, there are trade-offs, but for my shooting, it's a real pleasure.