Lots of good comments!
I own a few Greek instruments, a very old House of Stathopoulo lute, a small size Tzoura (3 course mini-bouzouki, string length 64cm) and soon a 60s bouzouki I bought on line (currently being repaired) as well as a new one that I ordered from Athens few months ago, all 3 course instruments. I believe that Greek instrument making is reaching it's golden period, I know everyone talks about old Zozef instruments but there are some wonderful makers out there who can make great sounding, beautiful, as well as reliable instruments.
Yes,one of them posts on this site, I am happy to mention his name although I believe most of you know him.He really is very good.I am sorry to say that, I have seen some SAKIS instruments with really rubbish sound..although apparently there are some better ones.They make so many so, I guess they can't get them all right.
There is a big difference between the 3 and the 4 string instruments, both in playing style as well as in the making. I much prefer the open sound of the 3string instruments, they also have less tension, which means it's less likely for things to go wrong..
I know there is a whole different way of using Greek instruments abroad, different styles, tunning etc. I am not against that but we have to remember that these instruments are built for a specific tunning. We don't want to mess with that too much.Also, the top bracing is in fact tuned to certain frequencies. Use the right tunning and the whole instrument will be complimenting the harmonics much more (if properly made)
None of my instruments have a truss-rod which is another great thing some Greeks are very good at. It is a great art to make a solid neck that just..doesn't move. I have been very lucky with all my instruments.
I am happy to recommend bouzouki makers that I have met and trust but I don't know how this forum works, or if that would be against the rules.In any case, my advice is, find a maker that stands behind his work and is happy to talk to you before AND after you buy your instrument. Internet is a great tool for that nowadays and a quick search will reveal several makers and workshops happy to take orders and communicate in English.

a last thing: pick ups were mentioned above. Yes professional players cannot avoid amplifiers but most bouzouki players learn how to play unplugged and makers build instruments to have a healthy sound. If you compare instrument sizes from the 20's and today you will realise that the desire for a strong sound is much more pronounced in modern instruments.It is not true that volume is of secondary importance. Remember, the home of the bouzouki is the taverna!