Canon versus Pentax 35-105mm f/3.5 constant lenses

Both of these lenses have been referred to as a “Stack of Primes.” Are there reasons to prefer one to the other? Would there be any reason to prefer either over a Rikenon 28-100mm f/4 constant lens?

I am looking for an inexpensive but relatively good quality all-around lens with manual focus for use on a Nex.

Thanks in advance.