I often see an impatience by my colleague of the day about calling "positive climb". And i always wonder why. Normally all engines are working correctly, in which case there is absolutely no hurry to raise the gear at the first twitch of the VSI. And even with the often trained V1 cut it is better to assure that you are in a stable climb before raising the gear as it could be an even worse day if you do it on the first twitch and then some flying inaccuracy leads to a ground contact.
I was trained, quite long ago, to make sure by at least three independent sources that we are indeed positively climbing away from terra firma. Which seems to be a quite good idea in my mind.