I see a number of these "Communications/GSM Test sets on EBay and am thinking of getting one to add to the test bench. The HP 8922 is one, Marconi 2955 is another that were used in the past, specifically for industrial testing of GSM equipment. However, they are somewhat useful in general radio testing and have built-in o'scope, spectrum monitor and even a tracking generator. The HP 8922 seems to be the most interesting but was wondering if anyone has had experience using these? Thank you.