My father still sends a lot to Lamberts - there can be a bit of a turnaround time (usually several months) but everything has come back ok. I cut his better stones for him.
Lamberts will cut things too small to be worth a local cutters time so if you have a heap of littlies then they may be a good choice. As others have said, if you have anything bigger and better, I would strongly reccomend getting it cut locally. Yes it will cost more but if the cutter lives in the same country as you and you aren't satisfied then you have some redress - if they have gone to the other side of the world and not come back then there isn't much you can do. I heard of a lady who found a large, clean aquamarine crystal and sent it to Thailand - the cutters were not Lamberts apparently. When it came back, it appeared to be the slightest shade different. So she sent it to a local gemologist for testing. The result - synthetic green quartz. She was dudded out of a good stone with no hope of being able to do anything about it.
The quality of Thai cut stones can vary from more or less ok to woefull. The basic principles of faceting as we know them here can be ignored simply to get a heavier stone. They don't seem too concerned about "windowing" stones - we don't do that here. They also tend to be fairly run-of-the-mill designs and most things seem to come back as a round or oval brilliant.
Again, Lamberts quality seems to be better generally. But I think dad has still gotten back windowed stones from them.
But if you have a bunch of little 1-2 carat rough stones, you may find Lamberts satisfactory.
