We have an 09 Smart at work, paddle-shiftable automatic. It's a much smoother ride when you shift yourself - one of the complaints about Smart transmissions is that they're not very smart - very lurching gear changes, unless you're accelerating very slowly. Much smoother to do it manually.

In some cars I prefer the semiautomatic shifting. I find many automatic transmission annoying, as they're always trying to 2nd guess what gear I want, and are too often wrong.

Yes, I do shift myself, but not if I'm just going in a straight line.
The problem is the car can't see what's coming ahead, it just reacts to you. There are times when you're reacting to the road and changing speeds that you want the car to stay in one gear so you have fewer variables to deal with, or you want the engine to stay up on the power curve because you can see you're going to need it ahead. Driving through snow is an example, or driving the turn 2 to 3 area at Mid-Ohio. Same with my truck when I'm off road, I don't want it upshifting if I can see I'm going to need some power soon.

Do any of the vehicles with DIY/automatic shifters also perform an automatic engine blip to smooth the downshift?

Sherwood

If you downshift with your foot still slightly on the throttle in SMG cars, it will perform an automatic rev-matching blip

I've had 3 of these-all Acuras. I doubt if the 'manual' mode has been used more than 1 hour total. They obviously came standard with the cars as I never would order it as an option. These transmissions must be more expensive to manufacture and repair than a regular auto. Seems like it is a waste of money. On the other hand, I do enjoy shiftuing a regular manual.

Reminds me of the ricers who have a 4 1/2" tach mounted on top of the dash of their 110 hp honda with an automatic transmission, even though they have a stock tach in the dash.

Yes, the DSG rev matches.

I use mine for mountain driving...helps the car stay at the right rpm without flooring it all the time.
Other than that, it's useless to me.