You probably already know this Tony, but if you just noodle down on the log a short way with the chainsaw, then hit the log in those shallow cuts with the block splitter, it should split OK.
The MS180 is a very good saw! It cuts well above it's weight. Much better than the newer model, which is strato.
If you ever do feel the need for a bigger saw, I'd skip the 45-60cc range if it were me. I own three 36cc saws these days & used to have both a 52cc & a 45cc saw as well (MS260C & a Husky 345). My next saw up was a 7901 Makita. The jump in power between the 36cc saws & the 1st two was very, very small & the weight difference is significant. I found myself going straight from the 36cc saw to the 7901 when the branches got too big for the small saw. I sold the 260 & the 345 & have never missed them.
Food for thought on buying a larger Chinese chainsaw; I helped someone assemble the 72cc version he'd bought on Ebay. I'd rate it no more powerful than a MS260 & a whole lot heavier. The chain that came with it was junk. Once blunt, good luck on getting an edge on it again. He sold it.
Like I said, I needed a new bar & chain for another saw & the Chinese saw I bought came with an Oregon bar & chain for less coin than just buying a bar & chain, so I bought it. I doubt I'd do it again though.