At first I thought I was really lucky to have a supervisor that is commited to my project and that stays in contact and we have meetings all the time.

My project is pretty weak (as in anybody could do it) for the most part. But there has recently been a part that was going to be more challenging and I was looking forward to that. I was already seeing how good it will look if I managed to solve this in my thesis defence presentation.

But, before I had a chance to even look into this (we are talking few days here) supervisor has already contacted me to tell me that he has already found a simpler solution to this and that it's good for me because "other approach was just too complex" . I'm even going to ignore a personal implication here that he didn't think I was capable of the more complex approach and concetrate on the practicalities. Yes, his approach works well. Yes it's going to be a lot less work and will save me time. But it will keep my project looking completly medicore.

I'm just worried about my employment opportunities if I do medicore PhD project. Then again I don't want to "rock the boat" as I'm sure my supervisor means well and is trying to help and I'm worried about damaging perfectly good relationship.

Maybe I should just get PhD out of the way and concetrate on "proving myself" afterwards? Any thoughts on this?

In my opinion, your supervisor is absolutely right. He/she has the experience and knows what would be "too complex". Because if it truly is too complex then this could result in big problems at a later stage of your research and perhaps even jeopardise you getting a PhD.

Concerning job prospects with a "mediocre" PhD project. How do you define "mediocre". If it gets you through a viva then it isn't mediocre. Apart from the fact that it is only important to have a PhD to be employable rather than having a groundbreaking PhD to be employable.

Finally, I think you should listen to your supervisor in order to get a PhD and also read up what a PhD exactly is. Which is not a Nobel Prize discovery.

I'm with you, but I think it's normal. PhD's are invariably mediocre, they are mediocre by definition. A PhD is a document that shows that you understand and are able to replicate "the system", call it paradigm if you will. Your supervisor is right, and you are right too.