cloud9respect

OK, here is my story.
I bought a house last year that sits on an acre of land.
On that 1 acre, I have about 30 trees and so many hill that it took 6 tons of sand just to level out a place in my back yard for an above ground 16' box pool!
When I bought the house, it came with a 3yr old craftsman riding mower.
That mower always scalped my yard, even on the highest setting and after getting new blades.
So I sold it.  I have been push mowing the acre ever since.
Problem is, it really is no fun push mowing without any self-propelled mower.

So I am going to purchase either a Toro 20055 self propelled SR4 mower, or a Lawn Boy Insight Platinum 10795.
Here are the things I am not sure about:
1.) I will mulch EVERYTHING, and I need to know if the SR4 works better then the Lawn Boy at doing this.
2.) How powerful is the personal pace RWD on the 20055?  I need some massive power.
3.) Which mower will I still be most happy with in 3 years?

Any help or advice is appreciated.
Also, if you want me to look at another mower, let me know which one.  But my budget is $500-$550.

Thanks.