I don't consider myself an expert on making microfoam, but one thing I've found is that technique and timing tend to vary, sometimes a lot, from machine to machine and pitcher to pitcher (and even from brand of milk to brand of milk!)
Don't feel bad that you suddenly can't get great microfoam with your new machine. The amount of steam power and the tip configuration can make a big difference in determining what techniques work for producing the best microfoam. What you have to do is practice, practice, practice, trying different variations until you hit on the right methodology (true of espresso in general, IMHO.)
A useful practice technique is to fill the pitcher with water and add one drop of liquid dish soap. It foams in a manner very similar to milk.
Here's a post containing a video of Scott Rao demonstrating how to do it.What the video doesn't say is that you should practice with dish soap over and over until you can consistently produce silky foam without bubbles. It may take quite a few tries, but it's quick, easy and cheap to load up with another pitcher of dish soap solution.
I recently bought the Espro Toroid pitchers to give them a try. I had been able to make excellent microfoam with my Motta pitcher, but wanted to see if I could do it more consistently with the Espro Toroid. I was mighty disappointed when the first few attempts produced poor microfoam. Not bath bubbles, but a lot of small bubbles visible under the surface. It was only after about an hour of practicing with dish soap that I hit on the right technique. As it turns out, the technique is similar to what I use with the Motta pitcher. My mistake had been following the instructions that came with the Espro to keep the tip in the center of the pitcher!
(NB: the Espro pitcher is nice and ergonomically pleasing, and it has a different tip configuration that produces finer latte art lines than the Motta, but I wouldn't say it contributes to significantly better microfoam or helps me to be any more consistent than the Motta -- or any other pitcher, for that matter.)
You'll see in the video that one important part of the stretching technique is to position the tip so the sucking noise is gentle and intermittent. If you suck big globs of air in, you're more likely to stretch too much or get bubbles. Once the side of the pitcher gets to about body temperature, you lower the tip so it's just under the surface and the sucking noise stops. Position the tip to get as vigrous a whirlpool or standing waves as you can. This will incorporate the milk and foam. Often it helps to move the tip to the side of the pitcher, tilt the pitcher more, etc. When the pitcher begins to feel hot, turn off the steam, let the last of the steam escape the wand and pull the tip out.
The dish soap solution is a very good way to try different techniques and timing.
Note that the steaming technique varies, mainly in terms of timing, with different kinds of milk. So once you've nailed the general technique with dish soap, you'll need to practice with different kinds (and perhaps brands) of milk.
As has been noted, skim milk is a little more difficult to steam, comes out a little stiffer and tends to separate more quickly (and "bubbles up" on the surface within a few minutes if the microfoam isn't perfect.) But practice really helps: I steam skim milk virtually every day and honestly can do it much better than I can steam whole milk, which I rarely use.
As for brands, I've had the least success with cheap supermarket skim milk and the most success with high-quality milk from local dairies.
With skim milk. I find it's generally best to let the microfoam sit for 10-15 seconds before swirling the pitcher. If you overstretched a little, you might want to let it sit for less time; if you understretched a little you might try letting it sit for slightly more time. Then tap and swirl the pitcher. If the milk has been properly steamed, you'll get a beautiful shiny top on it.