I've been dealing with DSZ for about a year now. They offer a great range of products which I have built my business around. The delivery times are very fast with most orders being shipped same day or next day.
They are efficient in dealing with warranty issues and returns.
Most of the products seem to be very good quality.
Of course I would like some prices to be a little better as I am a very good customer of theirs and I simply can't compete against their parent company and be profitable. However, I can't complain at all as they have become an integral part of my business as my main supplier and my business has grown every month and hopefully will continue well into the future.