Well, with an introduction like that...
Steve likes to keep his hand on his stick constantly, I like to have my hand on mine when it's appropriate
I don't see anything wrong with using tip often, or all the time. All you are doing is taking over the decisions on when to shift from the computer(s). Other than that it's the same as auto shifting. Only prob I have is when I've got the stereo cranked at the lights and then take off forgetting it's in tip

. Thank god for rev limiters
My other favourite is the "Fark, thought I was in tip?" nudge up on the gear shift when it's actually in drive. I heard an Escort blow up an engine once by free revving it (ie no load on engine) and the thought of it scares the sh!t out of me. Only done it a few times, but it's not a nice feeling. Try not to do it often.
Other than that only danger to me is the down shift from second to first can be a bit rough at zero throttle if you hit it at just the wrong time (falls just short of chewing on your steering wheel, but not by much!)
I've done a lot of looking into the INVECS II (our tip box) and been amazed about how it works. Even read the technical manual section on it. I could give you a summary of the more interesting stuff if you like, but it'd be a fair essay and I haven't written one of them in 11 years lol.