I could afford a pair of no-brand tpu tubes like a year ago for my road bike. Though I feel I can speed up a little quicker than before with butyl tubes, the extra space in the case is great and they loss air much more slowly than butyl’s. Haven’t had any flat either so at least that’s great, but can’t tell if it’s because the nature of the TPUs or that I’ve been really lucky.

Some other pair for my mtb is on its way, but change its tires to wider and grippier ones, so I won’t be able to feel any difference there when speeding up.

The caveat is their price, though, they still cost 3x than butyls, at least around here.