IWC vs Rolex quality?

So, I (M39) have been thinking about getting a proper watch for some time now. I have narrowed it down to either a Rolex Explorer 40 mm or an IWC Mark XX 40 mm, both with black face. I also conciderd the Aqua Terra from Omega, but I like the other ones better.

I went to the dealer tody to have look at them. Like I told the salesman, I am not a collector, and I am not investing or placing money. I want to buy ONE watch that I can use with everything and that I will last me forever. I tried them both on and they were both amazing. I have to say that the IWC gave me a little extra warm fuzzy feeling inside. This and the fact that I can take it home immediately and don't be a part of that BS Rolex waiting list, and the fact that you can easily change straps and braces yourself making it incredibly versatile, really put me on to this one. It just felt right!

However, this is the question. I have heard of numerous of people who had their Rolex watches for 50-60 year and its still good. Is IWC a forever-watch?

FOLLOW-UP:

Wow. There has been tons of great replies here. I really appreciate it! Like I said I got a better feeling from the IWC and getting confirmation that it indeed is a forever-watch certainly makes the choise easier. BUT, a wildcard has come up! I know this is a IWC reddit so I don't know how well this wil go down, haha. I saw a Hamilton Khaki Field Auto that also gave me that warm fuzzy feeling! I know the IWC is in a completly different leauge, but the Hamilton certainly became a competitor! I know it probably isn't a forever-watch, but on the other hand, I can buy about 8 Hamilton watches for the price of the IWC. Ahh decisions decisions.

Anyways, again thank you for all the replies. It is most appreciated!