If by Cirrus, you mean the Micro Joule system, yes, it does work well. There were some serious teething problems with it since they were the smallest conventional servos made at the time, and the first batches were handmade and some were not all that well assembled. They worked like mad to get it right, but the market had moved and the bad rep of the early systems hurt their sales. Although the dealers (Hobby People) had the best return policy ('It doesn't work right? Here, take this one instead') people didn't trust it.

I have about 4 of their systems, maybe more, and I had to return a few pieces early on, but once it was working, it works great. Problem is, that they seem to be discontinuing the system. If you want to go that way, get extra parts while it is still available. It works very well in mid-sized micros. The main problem area with the gear was the servos. They have a rather complex drive train that ends in a bevel gear with a matching bevel gear on the motor. Alignment has to be accurate for them to function properly.

Since then Falcon (in the UK - http://www.falconmodels.uk.com/ ) has developed a much better system that is about half the weight of the MJ gear. Their line includes the 'Breeze' block which is a receiver and two integrated servos (4.8 grams with crystal and antenna), a descrete RX (1.8 grams) and incredibly simple and light 1.6 gram servos, a selection of 1 gram 1.5 amp ESC, brushless ESCs (<2 grams), and batteries that all have their 'IDC' connectors (about 1/3 the size of a mini-JST); all of their gear simply plug together.

Here is their photo of the 'Breeze', which measures 1" wide:



The servo is 1/2" x 1/2" x 5/8" long:



Here are two of my own poor photos, one showing the servo on a dime, the other shows two gliders that are 9/16" wide through the pod; the gliders use the descrete components. If you would like more info on these, just ask...