Can’t speak to the reliability of the Whynter brand, but if you simply cannot locate the hot parts of the air conditioner outside like with a window unit, a mini-split, or central air… and must use a roller unit… at least get a dual-hose model like this one.
Single hose models like 95% of the models sold, blow the hot air out the window, but have no second hose to replace the air they are blowing out the window. So single hose units suck in hot, humid air from cracks in your home/apartment. Single hose units might cool your room, but you’re also sucking in hot outside “makeup” air to offset the air you just paid to cool.
Dual hose roller units still have their hot parts inside your home, so they are not very efficient either… but at least their air paths are “closed loop”. They keep the hot “makeup” air they suck in, inside that second hose, rather than mixed with your cooled inside air… and as with single hose units, blow the hot air they removed from your room outside.
BTW, surprisingly, saw our local Home Depot selling a dual hose Toshiba roller AC unit. Certainly was more expensive. (“Toshiba” branded, but made by Chinese big portable AC maker, Midea.)