This is "just" an 8 inch, 25W speaker but you wouldn't know that from its sound. Jensen themselves describe it as having tight bass, aggressive mids and bright highs. They are not overstating.
Amazing bass response here, no muddy, boomy sounds but just crystal clear tone. The higher frequencies sparkle. Very defined and lush sound with single coils.
Sound is partly subjective, so to put things in perspective: I play a Fender Strat with Texas Specials through a tiny Kustom V5 Defender. I like my sound clean, or at most a little breakup. The speaker performs wonderfully here, it really opens up the amp, like removing a curtain in front of it.
Any negative points? Relatively speaking, no. For any improvement you'd need either a bigger speaker (12") or perhaps Alnico (though that is debatable).
If you have a practice tube combo, 5-15W, with an 8 inch speaker that can use an upgrade, this is it. Sure, you'll maybe end up paying 1/4th of what your amp cost, but to me, it's worth it. This speaker (together with tubes from TAD) has made the little Kustom really shine and become an excellent recording amp.