Although i do not have experience of the long cornet, the Shepherds hook cornet with a proper V cup mouthpiece blows nothing like a trumpet. This is why specialist cornet players rarely swap between the two on a frequent basis. Some top British cornet players that i know are terrible trumpet players. They make a horrible sound, but would melt the heart of an iron lady when they are blowing a cornet and Trumpet players more often than not make a horrible noise on the cornet. There is very few people that can stylishly swap between the two.