You normally don't replace the frame, just the door. They can be trimmed to fit the frame.

If you want to replace the trim, it comes off and the frame is still there. Nail the new trim to the old frame.

Don't buy "pre-hung" doors for this, just buy the door.

Buy the doors W/O them being hinge cut or drilled. Fit the door to the opening refraining from cutting the hinge side. Mark and hinge the door completing and further adjustments for fit and closing. Mark and drill the door for the lockset using the center of the existing strike as the index.

That being said, I would correct the door fit and create the door design of my choice, with molding.

I appreciate the input. Most things I read say it's much easier to install pre-hung doors rather than dealing with a slab so that's why I was considering that route. Plus, the previous homeowner had to shave a couple top corners of doors to get them to close because the settling of the house has left the frames just a tiny bit tweaked.

Installing new prefabbed panel doors without correcting those deficiencies would be noticeable in the finished product.
So, rather than remove a jamb that simply need adjusting, for a new jamb that needs to installed and adjusted.

Use a carpenters square to determine how the jamb is out of adjustment, by placing it on both jamb legs and held tightly to each corner of the header. carefully remove the trim so as to not disturb the paint joint from both sides of the header and the jamb leg that needs adjusting.You'll more than likely need to remove some shim material and finish from around the header jamb as well as nails to adjust the jamb leg.

Most of the corrective measures would also be required for the replacement door jamb.

In one case your money is still in your pocket, in the other, not so much.

The labor involved in replacing just the door slabs will probably be higher than the labor for installing prehung doors.

The hinges for the old doors are probably double, the new doors will need to be triple.

It is quite easy/simple/fast to install prehung square and plumb---and can be difficult to fit slabs in skewed frames.

"The hinges for the old doors are probably double, the new doors will need to be triple."

Only if they are solid core doors.

"It is quite easy/simple/fast to install prehung square and plumb---and can be difficult to fit slabs in skewed frames."

To some, craftsmanship is second nature.

Being a tradesmen takes far less talent.

Thanks for everyone's input, I really appreciate it! I might try do a slab and see how it goes. I have 11 doors to do so spending a few extra bucks to play around with one of them before making a final decision on the rest.

Snoonyb, you get a pass---I have built doors/frames from rough lumber, I have installed antique doors and French doors in new houses with custom built thresh holds and frames, and I have installed 20 prehungs in 8 hours that were checked for level and plumb by other craftspeople.

There is a HUGE difference in speed and craftsmanship, but a craftsman can be fast.

Many of my customers wanted speed. I gave them both.

Putting a new slab in an old skewed frame may well require a certain level of craftsmanship, but it certainly is not very professional.

Putting a new slab in an old frame that has been made level and plumb is both craftsworthy and professional.

Well handymac, there are some significant differences.

I work alone, all of the moldings match throughout the house, all the doors and moldings are painted with oil based paint and the debris have been disposed of.

Only if there are more than 10 doors will I take the doors to a door mill and have them hinged and drilled.

In 35yrs. I've performed 1 warranty call back that was not of my doing, I valued the customer.