Be aware that you will have a very different student experience at Heriot-Watt than Exeter. Heriot-Watt courses are typically very vocational and they have great employment rates. However, they are not in that 'top-tier' of universities, so exposure to some of the most competitive employers will be more limited. Although there may be slight differences in the courses I would be focussing on the student experience more - and what you want from the years you will be living there - it will be completely different. Heriot-Watt has nice facilities and small-ish campus but very little going on at the campus, it feels more like a college rather than a fully fledged university. However lots of people like a quieter environment. The students seem to go into town to socialise so could really be anywhere. Exeter will likely be a more immersive experience, a bit more like Bristol or St Andrews, and you still have access to wonderful beaches and the south west.