There are always going to be people with different visions and philosophies challenging the person currently at the top. It's life.
I think Sheriff Evans has done a good job since he's been in office. I see him out in the community all the time, and he is very accessible/approachable. I see him in Walmart and he's talking to folks. His deputies are all over the place. I live in PF and I see them out and about. Sure, I see them up and down Route 4 pulling over speeders. A LOT. However, Rt 4 is a huge problem with traffic and people using it as speedway in lots of sections. It's the main thoroughfare in and out of our county which is used for transporting virtually all kinds of commerce into and out of counties to our north and south and to the west via other roads. (i.e., Rt. 231 into Charles Co) There is a huge problem with accidents on Rt. 4 - from the north to the south.
Running against someone currently holding office doesn't automatically make one person worse than the other. The more competition, the merrier. I've liked and have been happy with the job the current Sheriff has done. I know him a little, have had some personal interactions with him politically in the past, in person in the community and also through my employment. I had no reason to NOT vote for him.
Conversely, I thought Kontra sounded like a disgruntled former employee, although I don't know a lot (first hand) about the "office politics" that I've heard rumors about. I thought in following some of the comments on the Kontra FB page, that a lot of the folks who posted looked like uneducated redneck idiots. (just my observations)