I find it depemds on the loco. Ive done 2 this week. First was a 37 decoder into the new yellow network rail 37. Jerky running at lower speeds and starting off. Made better with cv changes . 2nd was an 08 decoder into a recent green Hornby 08. This one runs very smooth, crawls beautifully and default setting have nice amounts of interia preprogrammed.
Im waiting on the Deltic TTS to see what thats like.