I have never heard the PSA sub, but have heard the LFM-1ex and can tell you the buyer sent it back, and bought a VTF3.. I have seen the VTF3mk3 compared to the PSA and people prefer the VTF3, now the mk4 is out and supposed to be even better, seems people like the tuneability and amount of clean low end it produces... plus it son sale... Google xv15 vs vtf3 and see if anything comes up....
I just prefer the HSU, because when trying out brands, they sounded awesome, I was willing to spend up to $1500 and the Vtf2 ended up being twice what I needed!!! Literally I have that sub turned below the half way point on the sub, and -6.5 on my preamp and at movie listening volume, I had to keep an eye on my mantle clock to make sure its not walking around {and its a 9 bell clock, HEAVY, I have since had my carpenter set a dowel in it to keep it still}.....
Plus HSU's support was first rate, hands down one of the BEST customer services in the business, and I always factor that in when buying anything. For the most part the ID companies have good CS.. Although when I was returning my demo outlaw sub and amps {I wasn't impressed with either}, I got a little attitude, but nothing blatantly rude...
Anyway, good luck, I hate to say it but, demoing a couple subs at the same time is the best bet... Although trying one at a time is nice, but you will pick the first one because everything you are looking at is top notch... For the money the vtf3 gets my vote... Although I love that vth15 and the uls15 sounded awesome with music...
