Cornsilk interior: We love the color, but are amazed at how much color transfer there is between our clothing and the light color leather and fabric. To be honest, we wear a lot of black (we're classical music performers, so black is the default for men, frequent for women) but in fact had the same issue with our tan leatherette on our 09 Jetta. As for 7 and 10 year old stains...the fabric inserts might prove to be difficult to keep clean.
Regarding the SEL vs. SE seats. After several visits to the dealer, sitting in both SE and SEL seats, I still swear they're different in shape. I think the SEL seats wrap around the shoulders more, but maybe it's the fabric insert stretching more than the leatherette? I like the shape of our SEL seats (early production...did they change the shape later? Doubtful)
The SEL nav is SLOW to the touch, quirky, but does the job once you've figured it out.
Yes, the SEL has the Fender system. It's nice, but i can't compare it to the SE sound system.
We like the wood trim (which is NOT plastic, but it is coated with plastic material) with the black dash and cornsilk seats. I prefer it to the brushed metal.
Dual-zone climate control? No big deal for us, we never use the "zone" option.
Remote start? I will never use it. My personal opinion is quite strong against the whole concept, as in suburbia, during the winter, all the cars sitting idle as they attempt to warm-up really stink up the neighborhood for those of us that walk in the morning (not to mention the wasted fuel, and the diluted oil during slow warm-up). Rural areas, where it's cold, it might be useful, but really, a diesel never warms up while at idle, and I just can't agree with remotely starting an engine in the cold, w/o a way to monitor the engine. Regardless of temperature, I just start it and drive gently.
Keyless start is just another gimmick. I do like the keyless entry, though.
All said, we would buy the SEL again, even with the observations above. Resale? Probably better with the SEL.