It largely depends on what you've read: how reputable the journal, how well-informed and genuine the researchers were etc. Some papers are written just for the sake of making one researcher's 'quota' or fulfilling the minimal requirements for a grant. It's not unusual even in the research community to keep rehashing old information.
I always take Wikipedia with a grain of salt, especially when it comes to pharmacology / pharmacodynamics / pharmacokinetics. I may be wrong though, so take my opinions with a grain of salt as well please.
Here's another way of looking at the issue though.
For instance, an example of the symptoms a cholinergic overdose would cause ('bradycardia, sinus arrhythmia, vomiting and respiratory insufficiency'), as opposed to piracetam's most common side-effects listed on Wikipedia ('anxiety, insomnia, irritability, headache, agitation, nervousness, and tremor'): http://www.ncbi.nlm.nih.gov/pubmed/14658400
Although not listed on Wikipedia, sinus tachycardia is another potential side-effect of piracetam, perhaps more common than bradycardia. Unfortunately I can't find where I put my Thomson Micromedex toxicology leaflets on piracetam, I'd look up more info.
Btw, I hope I haven't offended you, it's clear you put a lot of work into the article and are passionate about the subject.
I'm off to sleep, have an awesome day wherever you are.
