After reading the reviews for the 60-250 it sounds like it is one amazing lens. I would get way more use out of it for birding, sports, and even weddings. The reviews say it is sharp from one end to the other....close enough to a prime for me.
If the optics are as good as my 50-135 2.8, then I would not need any primes except a macro and 14mm possibly.
Like others say, it all depends on what you are using it for, but for me personally it is how many times it comes out of the bag that counts
Thanks
Randy