They are plenty good for what you want. They are steady and have a good way to hold the bags steady on the top plate. Match the bag to the stock. Flat on flat is of course the steadiest, but most of our rifles are not flat stocked. Buy the appropriate bag (A little pricey but very good IMHO), and fill it with fine sand. I like heavy sand, and they sell it as well. Aluminum is plenty heavy for me, but some folks like the heavier cast iron. (Young men with strong arms and don't have to tote it all over the place.) If you like to shoot big boomers off of a rest, the cast iron might be a good thing. The slingshot is neat and I imagine for some bench setups might be needed, but the triangle is steadier. Is there enough difference to matter? Dunno. Thought about getting the slingshot aluminum non adjustable one as well. Already have the adjustable triangle aluminum. Used it yesterday with success with my .222 Mag.
For the price I think they are very nice and a very good value.
I modded the windage adjustment.