I would second the positive comments made above. I have been in 1C more than once and it's an excellent choice.
The E170/5 is terrific because it has most of the amenities of a mainline single-aisle a/c (minus, of course the IFE) including overhead bins large enough for a standard Rollaboard but in a small plane that is quick to board & disembark and without any middle seats in Y.
The biggest caveat I would note in FC on these planes is that, since FC is laid out 1-2 the overhead bins over the A seats are quite a bit narrower and your standard rollaboard will likely not fit there. Not a huge deal as there should always be enough room in the bins over the C & D seats.
I have also found the Compass f/a's to be a little less outgoing than the norm on DL these days, but my sample (about 10 flights) is too small to make any sweeping conclusions.
My most recent flight on a DL Connection E175 was DFW-LGA, which would be a very long flight in a 50-seater RJ, but was perfectly comfortable in the E175 (although the WiFi did not work in either direction).