I've had my Sigma 125 Roadsport SV for just about a year now and have clocked up 5000 miles just on general touring round my locale, with the odd trip further afield. My immediate 'upgrades' were a half hood and a shower cap, both from Softbits.
It's also no longer a 125 either! Premier Power worked their magic on it some 3-4 months ago, taking it up to a proven 155bhp with their upgrade package. In my opinion it's transformed the car. Still very easy to drive, perfect for touring with just that extra bit of grunt, but not so much that you're going to get into trouble when the road is wet and greasy. The engine note i perfect too! And as my skill improves I can choose to add on the 175 or even the 200 bhp package.