I am surprised you haven't found anything listing the pros and cons of pediatric spay/neuter. What does your breeder say?
There are several studies that show a correlation between pediatric spay/neuter with an increase in cancers, an increase in joint related issues (both hip and elbow dysplacia) and some behavioral issues.
Unfortunately, I just got a new computer and don't have all the bookmarked pages that I once had. I do have this link - you will need to download onto Adobe Reader the link at the bottom of the page.
Here are the pros and cons from that link.
On the positive side, neutering male dogs
• eliminates the small risk (probably <1%) of dying from testicular cancer
• reduces the risk of non-cancerous prostate disorders
• reduces the risk of perianal fistulas
• may possibly reduce the risk of diabetes (data inconclusive)
On the negative side, neutering male dogs
• if done before 1 year of age, significantly increases the risk of osteosarcoma (bone cancer); this is a
common cancer in medium/large and larger breeds with a poor prognosis.
• increases the risk of cardiac hemangiosarcoma by a factor of 1.6
• triples the risk of hypothyroidism
• increases the risk of progressive geriatric cognitive impairment
• triples the risk of obesity, a common health problem in dogs with many associated health problems
• quadruples the small risk (<0.6%) of prostate cancer
• doubles the small risk (<1%) of urinary tract cancers
• increases the risk of orthopedic disorders
• increases the risk of adverse reactions to vaccinations