Hi jcarr and welcome to the MRF.
I, myself, went through the same soul-searching dilema a couple of years back and, depite wearing reading glasses, have no regrets.
OK there are limitations with regards to built-in sound but, as Edwin comments, there are fixed speaker systems which, while not perfect, are, lets face it, a damn sight better than anything available in 00 as little as 5 years ago. You could, of course always model American which would, indeed, give you the facility for in-built sound. Given time I think someone will come up with a solution to the problem. Magnetic couplings can also be a bit of a problem but I'm using the DG Couplers now (having failed miserably to get the Microtrains/Kadee type couplers into N Gauge locos) and have no problems either with their operation or aesthetics.
As regards DCC control chips, there are some amazingly small, yet still fully functional chips around these days. Have a look at the Elekroniks range, particularly their DCX74Z which, since it is designed to actually fit into a Z Gauge loco, will fit into just about the smallest N Gauge loco you can think of. I have several small 0-6-0 s which are fitted with this chip and they run like a dream.
The big attraction for me is scale length trains which run 'through' realistically proportioned landscaping. I don't think of N Gauge as a means of just getting more track into the same area but rather a way of being able to produce a layout in which the presence of trains appears to be 'natural' rather than 'imposed'.
But then I'm biased !!!