The mouthpiece is definitely better than the stock mouthpieces on low-budget horns.
I found it a bit muddy on the high notes and the lows (C, B, Bb) can be challenging for some. I upgraded to a Selmer S80 C* after that and I found it much better sounding on the highs and lows. The latter were a tad easier to play on the latter.
All opinions on mouthpieces are very individual and personal. I know people who praise that mouthpiece. It wasn't that suitable for me and my mouth features probably.