Generally, synthetic teak can be 30-50% cheaper than real teak, depending on design and quality of the real teak of course.
Synthetic teak performs the same function as real teak but often can be used in situations where real teak can't... for example conforming it over oddly shaped GRP.
Synthetic teak decking like Flexiteek 2G, is UV stabilised meaning it will look fantastic for years, unlike real teak that fades rapidly in the sun. There is also plenty of scope for custom designs and colours to suit any boat.
With the increased pressure on natural teak stocks, there are environmental concerns that ancient forests are cut down to harvest it. Synthetic teak has none of those issues and is 100% recyclable.
Far less maintenance is required with synthetic teak - if at all, just give it a quick clean with a stiff brush and water.
Some modern synthetic teak products have been specially engineered to overcome the flaws of old. Synthetic can now have similar thermal properties to real teak.
Synthetic teak has superior non-slip qualities which makes it especially suited to yachts and commercial boats like cruise ships.
Most synthetic teak products, like Flexiteek 2G, are guaranteed for 5 years, but in reality they should last way beyond 10 years and still look as good as they day they were fitted.
Early synthetic teak had more of a flat colour and was easily distinguished from the real thing. But after more than 10 years of development, synthetic teak like Flexiteek 2G is almost indistinguishable from the real thing when it's built and fitted really well.