I had a few successful tank start-ups with Bio-Spira. I can no longer get to the lfs
that I got it from, so I have used a product by Seachem called Stability. I found that Stabillity worked pretty well. It's still a good idea to monitor your water and possibly do some extra water changes but I did find that it helped. Its shelf life is longer than Bio-Spira also.
I found Nitromax on DrFosterSmith.com. It does sound similar to Stability. I have no experience with this brand, but I see no harm in trying it if you want to spend the money. Since it is live bacteria, it may work well if most of the bacteria are alive and not lost due to shipping, temperature variations, etc.