I have this exact model on a 63 plate and I really like it as a short journey daily drive and it actually is pretty good on motorways as well.
I previously owned a Mondeo ST TDCI and a Octavia VRS (petrol) to put my following comments in perspective. I was worried when I first considered switching to a newer car with a smaller engine, but financially and family/work wise it made sense for my situation.
When I test drove it, I was pleasantly surprised the engine is not slow to accelerate when underway, really quiet and not terrible on fuel (but nowhere near the quoted figures). I generally get on average 42mpg combined. I do notice the engine when pulling off/out though, both the Mondy and Octavia were far more responsive as to be expected, but I have never felt like it was dangerously slow either.
I have recently done some longer motorway journeys (Cornwall and Sunderland to and from Stoke) and I actually really did not notice the lack in power, it accelerates to 70 without issue and further (not that I have ever tried of course). Cruising was comfortable and the DAB/Navigation are both features I could not live without now that I have had them.
I would not hesitate to make the same purchase again in my situation (20-30 miles per day stop start) and longer journeys at the weekends. I also considered the 1.6T but after owning the 1.0 125 for 4 months I doubt I would have liked it any more.