Army or Navy Reserves

Hello, does anyone have experience with being in both? I wanted a Seabee rate with navy, but I know with Navy it’s not a guarantee to select your mos/rate. I wanted an engineering or CA mos with army. The process seems a lot faster to go with Army at this point, I don’t want to wonder if navy has a rate available at Meps , where as army will tell me exactly what I can do. I wanted to see what would be the biggest differences between the two branches reserve wise.