Yes it is contrasty wide open. The lens is from 1990. Got it cheap on an Ebay auction, where pictures showed a dirty lens, but the glass is clean, like new.  And after a day polishing with a tootbrush the whole lens looks like new now  
 
 The 105/2.8 shows sometimes a very small amount of chromatic aberration but easy to correct.   The quality of the images surprised me in a positive way. It's my favo macro lens at the moment.