I ride in very thick traffic in and around San Francisco all the time and yes, the clutch lever is quite stiff. The first few weeks I rode the bike were virtually hell, my arm would just kill me after lots of clutch play in traffic. Six months and 7000 miles later I don't even notice the clutch anymore. In fact I like the fact that I have to put some effort into it. I wouldn't worry about it too much, you will get used to it in time.
I had the same problem my first couple of weeks and I was terrified (of not being able to ride my Monster). it was also interfering with my work. I bought a Yoyodyne slave, but by the time I actually got it installed, I was already used to the clutch and no longer experienced pain. Not to say that the new slave isn't nice and helpful - I am very pleased with it - but like others said, don't worry about it, you'll get used to it. Oh, and I'm also very happy with my CRG adjustable clutch lever which has mysteriously reduced pull effort and increased comfort.
I know there was a recall for slave cyl's for 01 monsters (dunno if other years had the same recall). Maybe if your dealership is nice, they would let you pay the cost difference between a 3rd party replacement and throw it on for ya. I wish I had asked when mine was replaced. The stock is ok, but I'd rather have a "less stiff" clutch.