It has worked great for me and the only thing I may change is to drop the lift a few inches. I originally acquired the truck with a 6 inch lift. However, as it is it still works good so I not too inclined to change it yet. Its primary purpose is extended camping trips and backcountry exploring as opposed to hard core rock crawling, but it will go through anything I care to take it so far. I have no regrets ditching the IFS. However, I can think of lots of mods I would like to add. A never ending project, but a labor of love.
Also, my earlier statement may have been misleading about the price. As 1meanaz surmised the cost included a lot more than just the axle. It had some major surgery including custom steering, new driveshaft, wheels, brakes, bumper, new springs, ARB diff, bracket fab, frame reinforcement, powder coating, and of course quality labor. But enough of that.
Also for those of you who are interested, RPM now offers a straight axle conversion kit for F-150 (1997-2003) for $700. Apparently my truck served as the guinea pig. Of course you can expect to spend a lot of labor and will need more than what is in the kit to complete the transformation, but I am sure many of you here can do it. As far as I know it is the only one offered on the market for those years on a F-150. And believe me that I looked hard to find a kit until finally giving up and going custom.
Here is the link.
http://rpmfab.com/products-page/f-150/