I've had sliders and bifold both in the past, hate them both. My WIC now all have standard 30" raised panel wood doors and I would never go back, personally. I built out an unfinished basement in one of my rental houses last summer, trying to be cheap, used bifolds again in a 40" opening. Literally 1 month later they were torn off the track already. I replaced them with 36" hollow core to match the rest of the doors in the basement (9 of them) and they are kicking ass. The way the sump basket and lift station were situated down there, I had to frame out around them but they were located in the family room so I made it into a 7x3 closet of sorts, with one RH swing and one LH swing door, 32", meeting in the middle to have future service access to each basin/pump. Worked out really nice actually. I'd share pictures but I handed the keys over to the new owners literally the same day I hung the closet doors and didn't take any. SO short story long, unless swing space is an issue, I'd avoid anything on a track unless it's an exposed "barn door" style slider