Yes I would steer well clear of screwed or bolted tangs. The join between the blade and the stud/bolt, under the quillian, is a weak spot and has a habit of snapping apart 
Full tang with a hot peened pommel is absolutely the way to go. 
G
I would agree with you, Sir Gerard, if we were talking about swords where the tang's welded on, or at the worst, a threaded rod welded on. However, the Hanwei/Tinker line of swords are hand-forged with a full tang that is drawn down to a softer form of steel than the blade itself to better absorb the shock of contact...the threads are added after the forging process to the end of the tang to accept a sleeved nut. As with all things threaded, there is the possibility of it coming loose- but I can't say its the norm. I put mine under heavy usage, including blade on blade sparring with no ill effects and no rattling. It has come slightly loose during these times but nothing a turn or two of an allen wrench won't fix.
These were made primarily to allow customization- you can switch out practice blunt blades for sharps when transitioning between forms/sparring to cutting exercises, not to mention guards, grips and pommels (so long as the pommel's been channeled for the sleeved nut). Having the ability to purchase JUST the blade (as opposed to a whole sword) is a cost-effective way for some to continue to engage in the sport they love w/out breaking the bank.
Of course, I'll allow that the full tang hot peen is the safest and strongest way to go, but the H/T swords offer something those peened ones do not so in the end, personal preference will out.
