2003 Volkswagen Jetta 2.0 underpowered?

Just test drove this car. On the surface it didn't seem too underpowered, but there are a lot of reviews saying the car is "severely" or "horribly" underpowered with the 115 hp engine. I mean, it was a bit slow going up a really steep hill but it seemed to pick up fine and all. I'm mostly going to be in a flat city in a different state, with a few long highway trips throughout the year to go back and forth. I can get a great deal on the car. Should I do it? Will I be able to cruise at 80/85 on the highway?