I am happy with the aluminum spacers on my 4runner. They have threaded holes in them where you put 3 bolts through the top frame mount instead of studs like the ones you have pictured. I've had them in and out a few times over the last 8 years or so and I am surprised the bolts haven't seized in the aluminum yet. I suppose I could just put studs in the spacer and use nuts up top.
The rubber ones I had on the Tacoma gave me some trouble when I went to replace the struts. They were held in by removing the studs out of the top strut plate/mount, and installing longer bolts (not studs) that go through the rubber spacer and mount to the frame with nuts like factory. The problem here was that the longer bolts just spun when I went to take the nuts off years later. Made it a real pain in the ass with the limited tools I had on hand.
The ones in your picture look like better quality than either setup I have used. I would go for those if they are the size you want and it's convenient enough to purchase them.