Join Date: Feb 1999
Location: San Jose, California, USA
Programs: AS 100K, UA MM, AA MM, IC Plat Amb, Marriott Gold, Hilton Gold, Hyatt Explorist
Posts: 3,146
I did the Oman eVisa online in February 2017. The process was pretty painless, although the Web site was a little wonky (as many government Web sites seem to be). I paid with my American credit card and printed out the receipt, and it was accepted without comment when presented to the immigration inspector.
The only advantage of the eVisa (as far as I can tell) is that you pay the visa application fee online instead of paying it when you get there. On my last entry, the line to pay the visa application fee was almost empty, so the eVisa didn't really save me much time. I suppose that it gets one more bureaucratic process out of the way, which is always welcome.