I have a Gong HIPE Cruzader 6'6" and 7'11", 2025 version. I've foiled well over 1000km on them.
The 7'11" was the first one I purchased and dramatically accelerated learning -- I previously used a North Seek 118l, which was crazily wide and hard to get on foil. With the Cruzader I instantly went to foiling nearly all the time, but that was a shift in board shape rather than a reflection of its inflatable nature. I find the board is really firm with the carbon plate extending the whole length of my stance. A solid board might be a bit easier to get up on foil ('destick'), but I've not really found it a problem.
The main disadvantage I've found is that when I'm getting up in breaking waves, the thicker sidewall presented to the wave can take the board away from under me when it hits. But its not too annoying and once up on foil its a non-issue.
Now that I'm a bit better, the 6'6" board is a bit nimbler and almost as easy to get on foil.
Other big upsides:
1. cost, e.g. the 6'6" cost me $850AUD landed at my door. Comparable hard boards would be about triple the price.
2. robustness, with my North Seek, I had several falls where I hit the board edge with shins / elbows etc. that needed epoxy/glass work. With the inflatables they are pretty indestructible.
3. The gear fits in my car boot and lives there permanently, if the wind is up I'm ready to go (I can see the ocean from my office window so can adapt my plans).
My main concern is about an unscheduled deflation event :-). I'm often 5km from shore (note, there is always land downwind of me). I'm certain I could self rescue, but it could be painful. (I wear a PFD and carry a PLB, phone, dry set of clothes to wear in an Uber and leave enough contingency time to swim to shore in daylight hours -- yet to need any of that!). In various discussions I've found several others that have put 1000s of km on their HIPEs and used them for years. But not a single report of a significant leak. So the risk seems low. Just as long as a shark doesn't bite it, like happened to the foiler in WA!