Keyword stuffing is a waste of time. Not only will google catch it but onsite SEO is only a tiny part of what will get you up there.

It's just a matter of time before Google notices and your rankings will drop.
Trying to game Google is not recommended.

Don't worry about those sites that rank higher than you due to "keyword stuffing". They raise quickly but don't stay there for long. Just work on your onsite SEO and update your website frequently using your keywords of choice.

On-page SEO, such as keyword stuffing, will not get you ranked high. On-page SEO will only act as a bonus. Daily links will get your site higher in the search engines.

Yeah, don't do keyword stuffing. Long term (which is what you should be after), your sites won't rank well. And like SEOArbiter said, concentrate more on off-page factors like link building.

Exactly. Google will find out what you're up to, sooner or later, and you'll lose the temporary boost. Plus, it doesn't really matter if you're high up in the rankings if visitors are so turned off by your keyword-stuffed content that they leave quickly, without buying anything.