I used On-x for four years, with the upgrade to all states, etc. I find it is an excellent product.
This year in June, I signed on with Base map and had a week to compare.
Trekking into the Tillamook forest, I found it to be just as reliable and useful, and downloading of maps for offline use was easy-peasy, as was On-X.
Both seem to be slow in updating land ownership.
I've noted that with On-X, it shows roads where there aren't any.
With BaseMap, I've wanted to create layers for my own hunting territory, but cannot. I remember doing that with On-X.
IMO, both are excellent products. Basemap is 1/3 the price for multiple states, and I'm a cheap bastige.
What I found with both, starting with Onx, is I really appreciate the property lines. I translate that information to a paper map that I carry with me pulling out and powering the electronics when needed. I prefer a transit compass for direction and orienteering.