I am a big fan of the Seinfeld series overall but I think these first few episodes are the weakest of the nine series that were produced.
The character development as the programme progressed was no doubt influenced by audience reaction and as is often the case if a show can get past the first series it can really blossom into a great show (see Blackadder for the best example of this). Clearly the Kramer character (or Kessler as he first appears) was not intended to be as integral a part as he ultimately proves to be. The episodes feel a little dated, although they are more than 20 years old now.
Jerry Seinfeld was a stand up comic before this series and still is I believe, and as such it does take him a few episodes to seem natural in the roll.
Nontheless it is still enjoyable to watch, the three main characters Jerry, George, Elaine and later Kramer interact well and the much publicised 'show about nothing' developed into one of the biggest sitcoms of all time.
Series 1 is usually packaged with series 2 and goes for about ten english pounds on Amazon, well worth it I would say. Series 3 can be bought on its own for about the same but it is more episodes, 22 I think.