Buying a pair of 414's is a pretty safe investment. Well known brand and product, always sell used for a fair price and they tend to last for years on end.
I chose to buy a new pair for a studio project as I was after a clean and closely matched pair to use in stereo recordings, with the ability to select polar patterns for different applications.
Having used a lot of previous generations of 414's, I was aware that some people dislike the newer generations sound. I can only speak for myself, but I was happy with the sound I got from this pair of mics. The stereo pair were very closely matched, much closer in terms of frequency response than many other matched pairs I own.
These new ones sound great for all things acoustic and the in-between polar patterns makes them a lot of fun to use.
My only criticism is that you can't check polar patterns, pads and filters before you send phantom power to the mics as they are indicated by LED's, I actually preferred setting these with switches as it's a hassle - particularly if you have them set up high on larger mic stands.
The mics themselves are great in terms of build quality, but the shockmounts don't last when used daily sadly. A nice touch with the stereo set though, is that AKG also include standard mic clips to put them on for use when you need to squeeze into a tight space. A quality AKG stereo bar is also included.
The flight case is also a nice touch, but the clips on these don't last. They have changed the clips for cheaper ones sometime within the last 3 years.
Overall though, these are great sounding, flexible mics which won't disappoint. My favourite application for these is acoustic piano. The only thing I rarely use these on is vocals, I tend to prefer something with more mojo (but that naturally comes with a cost).