I'll give the plenor a try. I really liked the illusion of going normal rook with banded and scaled and if laning with another rook by the time it is the 1750 gold for vlemish time holding out for a while longer and then showing up with banded, scaled, vlemish and unbreak or even banded, scaled, unbreak and nimoth w/ mana pot.
Yeah - the illusion is a good thing. The downside to this is now that I've discussed the build here, the tier 1 folks will generally know the favor I'm using if I appear with 1900 hp and then will be extremely aggressive pursuing me for an early kill... which means I have to be much more cautious than I'd prefer, but challenges are fun, too. Anyway, the disguise would serve a useful purpose, but then I'd be giving up the mana advantage and basic early strategy.
I'm going to toy around with it to see how many people on my team I can piss off and how many times I get called noob seeing the MCP with rook.
heh - I haven't been called a noob yet in game using this build, but I will do my best to get that label 
Did you just use normal tower build?
Depends on what you mean by that, but more than likely, yes - just varying 1 or 2 skills at diff times (but all I get are towers/boulder/splam/arrow(trebucet)/ strength upgrade late). Odds are you use a build similar to mine as most rooks follow the same basic pattern.
I have only ever seen Reg use the MCP and I don't really know what standard play with it is, if there is such thing, but the few times I've seen it the Reg bought every cit upgrade there was. FS 1&2 currency1 2 exp 1,2,3. So instead of all that crap other than the FS 1 and currency 1&2 just buy gear for the others and still be able to keep a decent kit for himself.
Good reg's typically buy the vast majority of the citadel upgrades and isn't always in the think of battle as the front line guy, so he's a good candidate for mcp. If I play as reg, I know I'm on the hook for fs1/cur1 at the very least, and then creeps. But with the cost savings from mcp, the reg can purchase more and more.