How about an option for 'neither'. There may be some in the fandom who are bothered by both, including myself.
To me, no factor of a successful show should be rushed, unless it is justified. There have been both rushed captures, and evolutions that provide ammunition for this argument. A prime example for me would be Ash's Krabby. Although the focus at the time was that Misty and Brock were teasing Ash about not earning/catching enough Pokemon, thus he went to find a Pokemon (i.e. Krabby), it was obviously a rushed capture. This is because it was Oaked more-or-less straight after its capture. This may have been to showcase the whole '6-in-your-party-at-a-time' thing, but the fact that we didn't see it in a battle til the Pokemon League just shows how poorly planned the capture was for the future.
And this brings me to rushed evolutions, where once again Krabby can be used as an example. All that we had seen of Krabby since its capture were a few cameo appearances alongside Oak, until Ash decided to use it in the Indigo League. In its first battle, it miraculously took down a number of Pokemon, and then evolved to Kingler. This raises the question as to how Krabby had enough experience to achieve this all in one battle. This is perhaps evidence of a relationship between poor planning of the capture, and for its future in the show.
To a lesser extent, I thought that Charmeleon's evolution to Charizard was pretty rushed, but i'll excuse that seeing as the manner in which it evolved was pretty darned awesome lol.
Finally, I'd like to say that perhaps the writers have since learnt from their mistakes of making rushed captures/evos, which is arguably evident since AG. Rant over.