I know exactly what you mean. When I started I had a crappy Silvertone starter model, which was good to learn on, but then I tried out a Les Paul at a guitar shop and I knew the difference immediately.
The Samick guitar feels somewhat comparable to a real Explorer, the main difference being the pickups, which I mean to replace very soon, but the playing quality is great.
On the topic of beginner guitars, what's your take on that Behringer package that I've been hearing about lately?