I use the Henry Milker, when I'm milking. I have had very good results and the does are generally fine with it all. Now, this does keep constant pressure but has a gauge and it's easy to fluctuate. As the bottle fills, the pressure does go down some. One doe has little left and I rarely milk that couple squirts out. Others are FF this year and not sure when/how that will work.
The first milker was for one teat, then I bought a set for both at one time, not used yet as main milk doe was drying up & others have just freshened. There is no bottle to have under the doe, very nice. My Saanen gives so much that I need two 1/2 gallon mason jars to contain milk in order that I don't have to open any jars during milking. I have a basket on the side of my milk stand that will hold both. Plus, with this system you can get under the shorter does. A tube brush comes with the set up BUT I found a longer one at Hoegger (18") and can use at each end to get entire tube. Fast and easy, really. Then hang them to dry with jar lid on one end and teat cup on other. I had them make my lines longer than the "norm" as my full sized does were taller and I wanted to sit jars in the little stainless steel basket. No charge, just sent note as soon as order placed. Shipment very fast...like 3 days and it was here.
Generally I will just have two sets ready for use and switch the pump from one to another for 2nd doe. Like I said, Ivory fills hers nicely....most milking 2 qt size not enough, thus 1/2 gal used. Inside I pour one to fill one of the large jars, balance into a qt size. Easy and throw jars into dishwasher.
FEM the 2 teat system does have a valve in the lines to allow one side to be shut off and you actually start one side, then the other. Look on line, can buy valve as a part from HM. I always try to keep things that are more fragile...gaskets, tubes, on hand. I've even gone & bought a brake line evacuator pump from auto supply once. Worked great....same deal, just had all the other stuff already. Now keep it as an ER backup for the THREE HM pumps I have.
The ole hands just don't flex like they used to! Little arthritis in the fingers is what creates issues....and the length of a teat. Those little gals have some tiny ones.