Just my opinion but the
Bathmate sizing is harder than it should be.
With the
X-40 over a certain size you will get the red rings caused by the gator. At that stage I caution the use of it beyond 30 minutes because the rings may begin to form blisters due to the pinch and the pressure. It's not that big of a deal, and in my case they healed in about three days, but I'm just saying that if you are getting the rings and you really push it (hour+) you can blister.
With the
X-40 under a certain size and your balls may get sucked up. So you'll have to babysit it to prevent it. It's a bit like getting slapped in the balls and I'd rather not having that random issue every morning.
Ideally we'd be able to order a
X-40 with better gator design, or a size inbetween. Wish it would happen.
Myself I am trying to transition cold from the
X-40 to the
X-40 but it isn't working out so well yet. So long as I keep to a 20 minute or so session in the
X-40 I can stick with it, and I enjoy that I don't have to manipulate it. Set it and forget it.
I suppose you could use the
X-40 as a second stage pump once you have pumped a bit in the
X-40, to have enough starting girth that your balls won't travel, but that removes one of the best
Bathmate features which is that you can incorporate it into your morning routine with no extra time or effort involved.