I'm still heavily invested in Paul C Buff, but since I've moved from my studio and doing a lot more work in the great outdoors, I looked at the need for HSS to bring more of my studio light control with me.
It's pretty hard to determine with significant rationality what constitutes "reliability" and "longevity." One could purchase on the presumption of "you get what you pay for," but I don't know that real experience bears that out--not enough actual data available. Nobody is testing flash equipment and collecting user data the way Consumer Reports does for automobiles.
How survivable are units from, say, a five-foot fall to concrete when a stand tips over? Who is going to do that testing between flash units? Is Profoto more survivable to impact than Godox? Or--if we're afraid of falls--do we have to carry spares for either one? In that case, may as well go with the brand that we can afford to buy spares of.
As Teamspeed points out, ultimate longevity may not even be a relevant factor, except as a pointer to shot-to-shot reliability, when considering technical advancements. Indeed, the only reason I've looked beyond Paul C Buff is because I've finally become convinced that Paul Buff himself was their only innovation engine--and he's dead.
Some things are happening at DynaLite--their Baja line looks interesting, but as far as I can see, they still don't do HSS. But again, when you're looking at new designs at the mid-price level, you're looking at Chinese-made stuff with unknown production factors. The Chinese can put electronics on the moon, but are they putting that quality into electronic flash? Which ones?
Customer support is my big concern, but I don't particularly see a deciding-factor difference in customer support from the moderately priced offerings from any company except Paul C. Buff. Getting the equal of Buff with any other company takes two or three times the money.