Their issue hasn't really been build quality, which from what I understand has been passable, but more along the lines of software and internals. They've consistently released phones that would have been great.....about a year before they were released.

A great example of this is their current xPeria x10 line. The build of phones is just fine, but their specs and software was badly out of date when they were released. They were released with android 1.6 on them at the same time other phones were already being upgraded to android 2.2 (in the states at least, in Canada they came out a bit earlier, but most other phones were already at 2.1 when it was released). That line is going to be updated to 2.1 over the next month, which is when 2.3 (or 3.0, nobody is quite sure which number they're assigning the next version) is likely to be announced and rolling out to a couple of phones at least.

There are more examples I could give, but that one pretty accurately illustrates the majority of the issues they've had over the last couple of years.

So, I'm less worried about the build quality, and much more worried about the software, and the phone having some good internals that can deliver the gaming experience people will be expecting from a Playstation phone.