I guess it all depends on what your trying to do with your rig. No one has successfully done a solid axle swap on an XK yet that I know of. Also these cv's will make your front axles just as strong as axes found in a solid axle. You obviously still don't get the articulation of a solid axle though but if you used these with a 4 inch lift you would have plenty of articulation. On an IFS the weak link is the cv's. This will fix that problem. Not only that but bad cv angles cause premature failure when off roading. These won't break even at steep angles.
OEM cv's from the dealer can run up to $300 for one. You can get cheap ones from your local auto parts store for like $60 but they are garbage if you plan on wheeling you rig. You will break one of those a lot faster then the oem ones.
Your tuner will not fix the broken cv issue. If its broke your jeep won't move until you fix it. Trust me. Take off you front drive shaft next time you got an extra half hour to spare and use your tuner to disable the traction control and you will see what I'm talking about.
I hear you! I would love a solid axle swap but you would need about $6000 cash to have a SFA installed.