I have the two, normally disk brakes and slighter better gear set
At work we started off with the base spec, and have gradually replaced parts with better things as need be. (we are all about cost effectivness, safety and durability)
The first thing that we wore out was the chainwheels (big cog at front) replaced with chain and cassette and pedals as they seemed to be made from cheese and we munched them in about 6 months, this was followed by freehub (the bit that lets you freewheel without you having to keep pedalling) and the grips were crap and fell apart within weeks (replaced under warranty). A couple are now running shimano 615 disk brakes after the original tekros were damaged by vandalism/riders running the pads down that much the pad backing and piston was ejected. Both brakes do the same job the shimano have a bit more feel.
Personally I'd stick with what you have and just carefully consider what you replace with as you wear stuff out....
Now you have a bike,,,, clean, lube, clean and lube.... Grit in your drivechain is your enemy. (Dont jet wash)
If you are mainly staying on the road you may wish to change the tyres to something more free running, the tractor tyres fitted as standard are good for muddy trails, but on the towpath, light gravel and made roads they will sap your speed and energy.
We run Schwalbe LandCrusier - these have domed profile and a pretty speedy on the road, but also have some tread that can bite in when the going gets soft.
http://www.tweekscycles.com/Product.do?method=view&n=3594&p=907601&d=124&c=4&l=2&utm_source=Google&utm_medium=Base&utm_campaign=Hybrid & City Tyres&gclid=CjwKEAjwueytBRCmpOyZ2L-xrG8SJADwH5c6V77wjErLWMGHeeOOl6bn1qAQNFqYhqsMrjm0G5TqBxoCQ-rw_wcB
You could also consider the marathon plus which i use on my commuter and run along toepaths and cycletracks as well as the road.
http://nextdaytyres.co.uk/details.a...1bwuhit1vyqnossaojeko-3n9matuglks7rocrkvw_wcb
Landcrusiers are about £12 each at my LBS and marthons about £20.
At this point in your cycle career spending £30 on tyres will make a bigger difference IMX than spending squillions on other parts.