Are artificial reefs really as “good” as natural reefs? What are the wider social effects of an art installation? Great questions. Of course, to fully and properly answer these questions, social and natural scientists would need to study this system and others like it. However, in their review of the literature on artificial reefs, Bohnsack and Sutherland (1985) summarize how artificial reefs compare to natural reefs.

There is a scientific consensus that artificial reefs are “effective fish attractants.” In almost all cases, artificial reefs had similar community structures as natural reefs, and in most cases artificial reefs also had greater fish abundance and biomass than natural reefs of similar size. 

In the USA, many artificial reefs are constructed of waste materials like coal ash and tires – but this is not ubiquitous worldwide; in Japan, for example, artificial reefs are carefully engineered to boost fish stocks. Particularly in the United States, not enough attention is paid to optimal design, construction, and placement of artificial reefs.

Artificial reef companies like Reef Worlds were created to address the gaps in artificial reef design for tourism. 

More recent studies have found that:
"Artificial reefs have similar compositions of organisms as natural reefs given time (in this study, 119 years) as long as the physical structures are comparable (Perkol-Finkel et al. 2006).
Finally, a more recent study found that having vertical rather than horizontal surfaces was more important for encrusting organisms than whether a reef was artificial or natural" (Knott et al. 2004).

The general consensus about the ecological impacts of artificial reefs v. natural reefs are thus that many artificial reefs are well-planned and have similar (vertical) structure as natural reefs, that artificial reefs can be as good or better than natural reefs at fish recruitment and overall biodiversity (Bohnsack and Sutherland 1985, Knott et al. 2004, Perkol-Finkel et al. 2006).

And, the social implications of artificial reefs? Early studies of artificial reefs ignored their socio-economic impacts. But, artificial reefs are constructed “primarily for the purpose of producing social and/or economic benefits,” (Sutton and Bushnell 2007, page 841) and so it is ironic that the literature has focused on ecological implications without paying as much attention to their explicit implications for human lives. This is changing, however; a literature review by Sutton and Bushnell (2007) finds a number of interesting socio-economic results regarding artificial reefs:

Artificial reefs tend to be used primarily by recreational fishers and divers (in the USA, Australia), artisanal fishers (in the Philippines), or commercial fishers (in Japan).The economic impact can be substantial: a study by Johns and coauthors found that artificial reefs in a single county in southeast Florida produced $962 million in sales, $502 million in income, and 16,800 full- and part-time jobs (Johns et al. 2001).
 
Cited:
Bohnsack, James A., and David L. Sutherland. “Artificial reef research: a review with recommendations for future priorities.” Bulletin of marine science37.1 (1985): 11-39.
Johns GM, Leeworthy VR, Bell FW, Bonn MA. Socioeconomic study of reefs in Southeast Florida—final report. Report prepared for Broward County, Palm Beach County, Miami-Dade County, Monroe County, Florida Fish and Wildlife Conservation Commission and National Oceanic and Atmospheric Administration. Hazen and Sawyer: Environmental Engineers and Scientists, 2001.
Knott, N. A., et al. “Epibiota on vertical and on horizontal surfaces on natural reefs and on artificial structures.” Journal of the Marine Biological Association of the UK 84.06 (2004): 1117-1130.
Perkol-Finkel, S., N. Shashar, and Y. Benayahu. “Can artificial reefs mimic natural reef communities? The roles of structural features and age.” Marine environmental research 61.2 (2006): 121-135.
Sutton, Stephen G., and Sally L. Bushnell. “Socio-economic aspects of artificial reefs: Considerations for the Great Barrier Reef Marine Park.” Ocean & Coastal Management 50.10 (2007): 829-846.