I loved using a reel mower back in my days of being a groundskeeper--it gave my legs a workout that rivaled a treadmill once I knew where the uneven bits of ground were (you have to mow at a brisk and steady pace to get the blades moving correctly). However, if you have grass abutting any sort of wall, you'll definitely also need some sort of edger, since (iirc) the margins are larger with the push mower than the gas kind.