I use a A550 and have all 3 lens as mentioned with both the primes @ f/1.4 in the following order of purchase (50/30/17-50).
My opinion is that the 50mm compliments well with 17-50 when shooting indoors. 17-50 good for general use, from large group photos to 2-3 ppl shoots. When I just need head - shoulders portraits, then I switch to 50mm which is really sharp, especially for the eyes and fantastic bokeh (which you probably know by now. So, in the end, my 30mm is left in the dry cabinet most of the times. 30mm seems neither here or there, sometimes it feels too tight for group shoots and sometimes too wide for portraits at a standoff position. When I try to make use of the f/1.4 on the 30mm over the 17-50, I felt it was too tough to manage the shallow DOF and most of my shots end up blur when there's movement.
Just my 2c worth.
Anyway, OT a bit.
Any bros ditch their tamron 17-50 for CZ16-80 and why?
Cheers