ham.....regular vs spiral cut

Is it a "raw" ham or a pre-cooked ham?  Both are available in the non-spiral sliced (bone in).  Prep will vary depending on what you have.

If it's a "raw" or "ready to cook" ham, it will need to be smoked to 160* internal temp to fully cook the ham (you can pull it at 155* as it will coast up during the 20 minute resting period).  If it's a "pre-cooked" ham, it is already cooked and is just being re-smoked to re-heat to serving temp (just like a pre-cooked spiral sliced ham would be).

I've cooked all three types at one time or another, but I have never used rub on a ham.  I usually spritz them with either a mixture of apple juice or pineapple juice mixed 2:1 with either Jack Daniels or Makers Mark.  Hit them with this every 30 minutes until just about done.  I then would either use a glaze pack that came with the ham or a home made glaze the last 20 minutes or so (just enough to caramelize the glaze).

Main difference is the cooking times as a "raw" or "partially cooked" ham will take longer and have to finished at a higher final temp as it's raw meat from the start.

As to the rub question.  I don't think it would dry it out, but again I've not used rubs on a ham (other than a finish glaze).  I see plenty of posts about people using rubs on both raw and pre-cooked hams, so it should be fine.  I really see how the rub will dry the ham out though.  It's just an extra layer of flavor on the outside and the main mass of the ham is very moist.  I would expect overcooking would be the main culprit in a dry ham.

PS.  Nothing at all wrong with a nice thick ham steak like you described!

Spiral cut seems to be the rage these days.  Nothing wrong with it if handled carefully.

I generally prefer my meat in one piece, including the bone when appropriate.

I have knives.

Good luck and good smoking.

I think spiral cut hams a a waste of a good ham. The 1/8 inch slices are too thin to serve for dinner and the cuts in the ham allow it to dry out while heating in the oven. Just watched a brand name ham company make glazed ham on TV. A thin coat of honey on the surface then a heavy sprinkling of white sugar  and melt it with a torch. The same way they make Creme Brulee. You just turned a $25 ham into a $50 ham.