I'm astonished at how well Carol trumpets play. The 4000H-YSS C trumpet is a very affordable trumpet, but it has a wonderful sound, great intonation and a comfortable blow. Coming from a large bore Bb trumpet, it took a little while for me to adjust to playing a C trumpet but I have been playing this full-time for about a month now and I prefer it over my other $3000 professional model Bb trumpet as it gets me closer to the sound I hear in my head.
The response is very good, the sound is very colourful, and it plays very comfortably for a C trumpet.
You may need to experiment a little bit to find a suitable mouthpiece match but I have found the Curry TC and TF cup mouthpieces to really play very very well with this trumpet. producing a very large, rich, focused sound with good articulation, so that would be my first reccomendation when moving to this C trumpet.
The second thing I would recommend is doing a valve alignment. I did one myself (you can find out how to do this through google) and adjusted the upstroke a little bit and it plays significantly better. When I first played it, I was having some issues with the 3rd space C not feeling centred and locked in like it should be, but after the diy alignment it plays perfect.
A very nice trumpet. I will probably upgrade to the 5060H C trumpet model in the future just because now that I've tried this one, I can't help but think "If this is the low-end model, what must their high end model be like?!!". I bet it's going to be a dream to play.