I'm using 1.25 inch eyepieces exclusively. My favorite eyepiece on this refractor is the mid-range ES 16mm, It is powerful enough to see easy double stars and faint galaxies, and wide enough to catch large objects like clusters. Sometimes, on a clear night, I use a Meade 5.5mm UWA on the moon or comets, and the Celestron 32mm Ploessl but the 16mm stays on most of the time.
One eyepiece that I never use on the DX 102AZ is Celestron's 8-24mm zoom. I like it a lot on my Z8 but on this refractor it looks dim and muted somehow.
In short, a mid-range eyepiece is a good addition to this telescope. If you get a high magnification piece <8mm, I recommend one with a wide field of view because by the time you focus and the mount stops vibrating (2-4 seconds) your target will be almost out of view on an eyepiece with a narrow field of view.