This product has been proven to work but be careful. Just because you use Biospira won't mean you can add a full bioload of fish right afterwards like the bottle claims. Add fish slowly and test your water to be sure it is safe.
Also, BioSpira MUST BE REFRIGERATED or it will die and not work. If it is on the LFS shelf at room temp it likely will not work. Also, it needs to be as fresh as possible. Only look for the newest and most recent dates you can find. Yes it has live bacteria but these bacteria need oxygen to live. Over time they will die without it and will not cycle as fast as a new bottle would.
Overall I don't know the value of using it short of POSSIBLY shortening your cycle time so you can add fish sooner. I have known a lot of people who have tried it and have had to cycle their tanks anyway and at $15 per 30 gallons, it can be expensive to use in a 90 gallon just to have it not work.
If someone really wants to make a good article get some and test it. See how long it takes to reduce ammonia to nitrites and nitrites to nitrates in a clean, brand new tank adding the recommend pure ammonia to the tank with just the biospira and a simple filter. I for one would really like to see the results of a truely scientific test of new, old, refrigerated and room temperature samples.