The Mio Spirit 685's near-£100 price makes it an unique proposition. But the 687 doesn't have such a notable speciality. Although you do get a reasonable range of extras for the £50 surcharge, the £149.99 SRP places the 687 somewhere between the 685 and TomTom's GO LIVE 825, which has much more sophisticated traffic and mobile data services, or Garmin's nuvi 2460LT, which offers a better screen and the best voice control in the business. So whilst Mio's Spirit 685 is a shoe-in if you just have around £100 to spend on a sat-nav, the 687 will have you yearning for a little more funds to step up to the next level. Our advice would be to let that yearning guide your decision.