Odd question... power compared to?

What speakers are you driving? How loudly do you play them? 
If money is an issue also try the Parasound A23. It's a very solid 120 Watt amp.

The few Macs I've listened to seemed bright and a little lean. Parasound tends to be warmer, and more full IMHO. Listening with your speakers is a great idea.

Aerial Acoustic 10T.... 

I'd go with the A21, certainly not the A23. A McIntosh amp capable of driving those speakers will cost at least twice as much. Also, first time I hear bright and lean in the same sentence with a McIntosh amp unless the amp was way underpowered for the pairing speakers. If anything, they tend to be more on the warm side of the scale, at least the ones I've heard/owned.

I would buy the 21 as I need the power... just a curiosity question really... I sooooooooo want the pretty blue party lights but ... :)

For the money you can not beat the Parasound. It has the same effortless nature heard in the JC1. Nothing bothers it. Frankly there is no Mac amp that I would take over it. Macs have a way over smoothing over fine detail giving them a warm easy to listen to character that appeals to a lot of people but the fine details get glossed over. It may be the output transformers which they insist on using in all their designs. They isolate the amp from stuff like back EMF and the amps are indestructible. The transient response and dynamics of the Parasound will blow you away.