I would encourage you to go with the X30. I am about 7.25 BPEL, and still have plenty of space before maxing out on the x30.
I also have the hercules AND the penomet, which is much larger. When you are standing in the shower, when the device is larger than it needs to be, it is heavier and can lose suction more easily. So there is this advantage to not getting a model that is larger than necessary. This is a disadvantage for me with the Penomet, it is way larger than it needs to be for me.
Also, by the way, I believe that the hercules model at a lower price is a much better value than the X30, and I have both. The Hercules model actually works better and easier for me because it is simpler, and the modifications on the X30 don’t really improve function all that much, in my opinion.
On thing is, you don’t necessarily want to go for higher pressure than already available on the Hercules model. I have the X30 model that comes with the pump attachment, and I don’t use the pump as I have realized that more time is better than more pressure.