Well when it comes to your one and only penis, you don't want to cut corners. This isn't like a haircut or a tan, this can be something life-changing. This is also elective and not without risks.
When it comes to girth enhancement, you'll want someone who has experience, expertise, and ethical practice (What I like to call the 3'E's). In order to be vetted by the PhalloBoards, a Clinic should have a history of the aforementioned "
E's". The
experience signifies an injection (and/or surgical) technique which has been refined over many years. Girth enhancement is as much an art as it is a medical procedure, all cosmetics ought to have a veteran behind the needle (this applies to PhalloFill). Expertise means advancing the field of male phalloplasty forward through innovation as well as possessing relevant knowledge in the field, which PhalloFill also exhibits. Lastly, ethical practice is important, not promising you unrealistic gains, taking a medically-conservative approach, etc.
As for the HA itself, see this authored by PhalloFill -->
What is a Hyaluronic Acid (H.A.) Dermal Filler and are they all the same?
PhalloFill in particular has a great rapport with clients and has had many years injection-technique experience. I'll let them choose to elaborate further on what they believe sets them apart, I just shared with you what I already know.
That all said, I'm not suggesting that the alternative Clinic you are looking at are unqualified at all, just that they haven't been adequately vetted and/or reviewed.