I've used a couple of SunLite brand bits and pieces. They're decent knockoffs of name brand stuff, comparable to SunRace in quality. The Sunlite SL-26 appears to be a knockoff of the well regarded Shimano BB-UN26 (which is also fairly inexpensive), so it's probably fine.
Might just need some break-in rides. The cartridge probably has a rubber or plastic seal and metal retaining ring, so there's bound to be some resistance at first. Put on a crank arm and you probably can't feel any resistance at all. When pedaling it might cost 1/2 Watt.
Depending on which engineer you ask, they'll either say sealed cartridge bearings are worth the very slight increase in resistance in exchange for reduced maintenance; or a drag and not worth the loss of performance. For my hybrids I'll probably switch to sealed cartridge BBs next time I overhaul 'em. Not sure yet about my road bikes.
BTW, some sealed loose bearing/cup & cone types can be a bit draggy. The rubber seals do add some friction. Some folks will grease the rubber, or use PTFE, moly, something to slick 'em up a bit. My big ol' heavy comfort hybrid/errand bike has draggy sealed bearings. I don't worry about it on that bike. It's worth the imperceptible drag in exchange for not needing to service it... like, ever. Maybe if something goes wrong. But I'm not gonna redo everything on a $100 errand bike every year.
But on my road bikes, well... let's just say I was one of those kooks who replaced the grease in my hubs with light oil or WD-40 just before crits or long fast rides. Probably made absolutely zero difference considering my very middling physical abilities on a bike. But it sure felt fast.
And I'm still the type to fuss and fret over every tiny point of friction in the drivetrain on my road bikes... while completely neglecting my hybrids. Waxed chains? Yes. Sealed bearing pulleys instead of sintered bearings? Definitely. But can I even be bothered to wash my hybrid once a year? Nah. Because the MAMIL urge cannot be denied.