Posting goes way back to the old hotrod days. I have posted early honda motors that require stiffening to make big power with floating sleeves. Posting is much better than block guard as you don't distort any of the engine components when fitting or apply any pressure on any surfaces. You only torque up very loosely. Block guard also creates hot spots which are not caused by posting. This is exaggerated because block guards sit at the top of the bore closest to where the combustion process occurs and where the cylinder needs high level of cooling. People with block guards often find they have to run less advance because of this in a street car to prevent detonation. Drag cars will usually run from cold.

You only need to post on the thrust side of the block and it is cheap to do and even the average mechanic should be able to do it as long as you have some threaded alu rod, correct size drill bit, epoxy and the right thread tap.

My experience with early honda blocks has shown they are reliable with a 2mm overbore and 20psi boost with static comp of 6.8:1. My personal opinion is that sleeve splitting in later blocks is more the result of poor tuning than poor manufacture.

Good luck