I’ve just seen this rather nice paper about TRIP. The article is from an Italian publication, so all I can go on is the abstract. As such I’m not sure how they searched TRIP and what other databases were involved. Irrespective of that it’s quite pleasing!

Bibliographic research of efficiency tests: analysis of the validity of the meta-database
Galbiati G, Casati M.
Prof Inferm. 2010 Jan-Mar;63(1):3-8.

Aims: The use of a meta-database as a first approach to bibliographic research can be just as efficient asinterrogating single data-bases of the litature. The advantages and drawbacks of the two strategies are compared .
Method: A comparison of the results obtained using an identical interrogation made using the TRIP meta-database and different single databases (15 of guide-lines, 4 of systematic reviews, 3 prevalently consisting of primary studies) made it possible to analyse these methods as well as to study 4 meta-databases and identify the most efficient one.
Results: Using the same MeSH terms in both strategies, the following results were obtained: 204 publicationsusing TRIP and 475 using different databases. Evaluation demonstrated the pertinence of 142 (69,6%) of the 204 found using TRIP compared to 185 (38,9%) of those elicited by single data-bases.
Conclusions: The TRIP meta-database yields a lower number of documents but with a higher degree of pertinency, meaning that the researcher employs less time finding pertinent documents. With respect to the traditional approach, beginning research by testing the efficiency of the TRIP meta-database proved advantageous.