After buying my 50mm F/1.8 II, I got this 28mm F/1.8. The build is small, solid and compact.
Swapping between 50mm is fast and easy because both are small and light.
Once confirmed I like my 50 and 28, I got 20mm F/2.8 for group photos. Then eventually also got other primes including the 35L.
But I do not find my 28 redundant because changing lenses is easier than 35L.
Hood removal and attachment is also easier than that of 35L.
I can forgive its slightly lower image quality than the 35L, but it is really good enough for event and general usages.
So 28mm F/1.8 confirm my preference of prime. Best buy after 50mm prime.
If not sure what to take, I will attach the 28mm on my 350d first.
I do not consider 3rd party primes (e.g. sigma 35 F/1.4) for color consistency.
Maybe I like it so much because i am just a general user.