Hey Jeremy, that's the easiest way to the top I'm pretty sure. That Arkose sanstone is so crappy that any other obscure route on the spire will likely be harder and scarier. I used to live a half mile from Monument Rock and never climbed the thing. If you're looking to bag the spire then the 5.8 is your best bet from what I hear. If you're interested in some other climbing in the area, there is a pretty cool crag about 10 minutes up the road I've been developing. Let me know & I can give you more info.
I was at Monument Rock on Sunday. There was a fixed rope hanging part way down the South face. There was also a beefed up fixed piece of protection just below the P1 belay stance. The fixed line certainly looks out of place. I haven't climbed the rock but the climbing up to the top of the fixed line looks easy.