I record our church services with 2 Ex1rs and an NX5U. The EX1r has significantly better image quality. There is less noise in low light and better overall clarity. Even though the EX1r has a shorter zoom, the iris and zoom are completely independant allowing you to use a fully open iris at max zoom.
We record directly to a computer through a multicam switcher, so the larger EX1R files are not an issue. With SXS to SD interface cards and low cost class 10, 32 Gb SD cards, the EX1R file size really isn’t as big of an issue as it was 18 months ago.
If you are dissatisfied with NX5U image quality, I would highly recommend an EX1R. The less convenient worflow and higher cost/weight is more than made up for by the better image quality. If you have to operate remotely, however, the NX5U with a remote commander is the only way to go.