We took on a new franchisee recently and bought a new full set of equipment from Gaps.
The Axeon HF5 membrane is performing badly 248 in, 18 out, 85psi boosted. All our previous membranes (identical setup) have been in low single figures.
We discussed it with Gaps and agreed that it's just outside acceptable (93% rather than 96%). So I suggested we send it back. Unfortunately their supplier now tests on return and if the membrane on their test rig slips over the 96% limit, we get it back and we're charged £150 for the privilege. We have no way of checking what their setup is, validating their results or even whether the item makes it properly into their test equipment (I'm not suggesting they don't test, just that we have literally no control or oversight of what they do).
Draw your own conclusions but do be aware of this.
I stress that this isn't a criticism of Gaps. This is their supplier.
Also be aware that there are RO membranes on Ebay for£139 (less than the cost of this test) that you can return for any reason within 60 days of purchase. We had one to try and after a few months it's producing at 6ppm (and my water is higher TDS than the franchisee in question).
Vin