When calculating a valuation for a business, what are the reasons to use a Discounted Cash Flow model as opposed to the Gordon Model? Is one model more applicable to certain business situations than others, or is there some advantage of one over the other?
Both models understand that the value of a company is the sum total of all cashflows in the future, discounted back to the present. They vary in their definition of "cash".
The Gordon Growth model uses dividends as a proxy for cashflow, under the assumption that this is the only true cash received by shareholders. (In theory, counting cash is meaningless if there's no eventual end-game where the accumulated cash is divvied up amongst the owners.)
The Gordon model is best used to value companies that have an established, reliable dividend. The company should be stable, and the payout ratio high. GG will underestimate the value of firms that consistently maintain a low payout ratio, and instead accumulate cash.
There are multiple DCF models. A firm valuation measures all cash available to both equity and debt holders. A traditional equity valuation measures all cash that can be claimed by shareholders. While the latter seems most intuitive and pertinent to a shareholder, the former is very good at showing what a company can do regardless of their choice of capital structure. A small add-on to a firm valuation is the concept of EVA, or economic value add, where the return on capital (all capital -- both debt and equity) is compared to the blended cost of capital.
The DCF model is more flexible (optimistic?) than the Gordon in its approach to cash. The approach can be applied to many types of companies, at every stage in their maturity, even if they don't pay a dividend. A simplistic, or single-stage DCF is similar to the Gordon. The assumption is that the company is fully mature, growing at a rate perhaps just slightly above inflation, forever. For younger companies a multi-stage DCF can be employed, where you forecast fairly confident numbers for the next 3-5 years, then 3-5 years beyond that the forecast is less certain, but assumed to be slowing growth, and a generally maturing, stabilizing company. And then the steady-state stage is tacked on to the end.
You'll want to check out Professor Aswath Damodaran's website: http://pages.stern.nyu.edu/~adamodar/ . He addresses all this and so much more, and has a big pile of spreadsheets freely downloadable to get you started. I also highly recommend his book "Investment Valuation". It's the bible on the topic.