How long/how many pumps does it typically take you to fill the tube?
It depends. If I am by myself and just experimenting/practicing, it takes 3 or 4 of the slowly pump and release with a minute or more pause at full expansion each time. A lot of times I don't completely fill the tube during these sessions. During actual sex if I pump and release a couple of times I fill the tube, especially if I have taken a small amount of viagra b4. I usually don't "waste" the time as a rock hard erection is the main goal during sex and I am eager to "dive in". She has never noticed the difference.
While experimenting I have found when putting the "lower" tension ring on the sleeve first that I may be hard enough with just the one ring. It seems as the foam sleeve is slightly constricting blood flow also. I have not as yet incorporated the sleeve into an actual sex session and will probably take a few more weeks of experimenting b4 doing so.
Soaking the sleeve in hot water for 5-10 minutes b4 using is essential. After soaking applying a liberal amount of the lubricating gel to all parts of the inner and outer surface helps slide it on and helps create a good seal with the cylinder and with my abdomen. My rule of thumb is, if I wonder if I have put enough gel on it I add more.