Frankly, when it comes to content, your best bet is actually to listen to your customers more than your competitors.
Find out both the words your customers use to describe whatever it is you offer, and the phrases they use to describe the problem(s) your offering solves, Use those words and phrases in your site content and copy.
Find out what their pain points are, and demonstrate how what you offer can make their life easier.
Find out what is keeping them from pressing that "add to cart" button, and answer their objections.
When you talk about benefits, back each one up with one or more specific features that make that benefit happen.
When you talk about how good your offering is, back that up with case studies and testimonials from actual customers.
Make your site as easy and intuitive to navigate as possible. Make sure your most important pages are the most prominently featured in both your menus and your on-page links. Keep in mind that visitors can enter your site on any page, not just the home page, so make it easy for them to "get their bearings" and figure out where to go next. Include prominent calls to action on every page.
If you're going to review your competitors' sites for content, they can potentially help in sparking inspiration for topics to cover. They might be using a descriptive phrase you'd overlooked, or pointing out a benefit you hadn't considered, or documenting a use for your product that you hadn't thought of. You don't want to copy what they're doing -- because you really don't know if what they're doing is working or not -- just take a look to see if you can glean any usable ideas you can test out for yourself.
Also, if you're going to review their links, it's not about "how many" or "what type." What you want to look for are specific links from good, reputable sources -- editorial links (that is, links that somebody else gave them, not links they "built" themselves). If they have any from sources that don't link to you, find out how they got those links. Did they join an association? Submit an article to a magazine? Get interviewed by the local newspaper? Submit their product for benchmarking? Donate to or participate in a charity event? Work out a co-op deal with other related (non-competitor) businesses?
Whatever they did to get those good editorial links, start doing the same kinds of things yourself. Eventually you, too, will have a reasonable number of good, editorial links yourself. Yes, it will take some effort, but it will be worth it in the end. Anything worth having is worth working for.