Its going to be a personal thing for you. Myself I prefer the rod mics, I think my rod set goes up to 32 or 36 inches, and I have no complaints. I just can't get the tube mikes to grow on me until you passed 3-4 feet.
I dont know if the rods are easier to "feel" with or it they're just a little less bulky, but I never use the tubes unless I have no choice. The tubes are supposed to be more rigid for larger diameter bores, which you are not working with. So if I were in your shoes I would not waste the money on a set of tube mics.
Only thing I will add is do NOT get the newer mitutoyo rod mics, last set I bought no longer used the collets to tighten up on the threads, but rather a "hydraulic lock" which means the inside of the mic basically has tar or sticky grease on the inside to gum things up to stiffen the thimble. I traded them for the Moore and Wright little tiny .5 to 2 inch set and bought the bigger 2-32 inch set from starret and it has served me well for years.
I also find the tube mics are cumbersom to assemble, the ones I've used you have to constantly screw and unscrew various tubes to get to a length. With the rods, you turn one screw and drop in the rod with a spacing collar if you need it and tighten the screw again.
Just one mans opinion.
