If you fancy a bit of leather and a more upmarket feel then go for it if you don't mind paying a bit more.
If you want the 75ps engine instead of the 60ps engine for the extra power then I'm not sure it's that much of a benefit.
Although I like my High Up, when I drove a 60ps Up I was pleasantly surprised. The 60ps car has higher gearing so it's quieter on the motorway than the High Up. On paper the High Up is quicker but I never noticed the difference.
It's Your choice, but apart from looks don't expect the driving experience to be a lot different.