Rexter,
The G27 appears to me to be small enough to carry comfortably, loads an acceptable amount of rounds and propels a powerful .40 bullet.
Respectfully I ask you, what did you find to be a disadvantage about the G27?
The G27 is FAR bulkier than an SP101! While the overal length, width, and height equation may seem to make compact autos equivalent in size, the protruding rear portion of the slide of a Glock, or any striker-fired auto, adds a whole new dimension to getting the weapon clear of a pocket. A spur-less revolver wins the draw-speed race more reliably. When a weapon is serving in the secondary role, if I need it, I may well need need it VERY quickly in a very desperate moment.
Moreover, a secondary weapon may be deployed during a physical-contact struggle. An opponent who grabs the slide of a baby Glock may have a better grip on the weapon than I would. A revolver is the opposite; if I have a hold of my SP101's tacky, stickiier rubber grip, an opponent's sweaty hands will only have a limited amount of slippery steel to grasp.
Please keep in mind that I am talking about a secondary weapon. Moreover, as a peace officer, I have a duty to get closer to bad guys than would a private citizen. My needs are not necessarily the same as those of anyone else. My way is a way, not the way, to quote my teacher, SouthNarc.
As for the power of the .40, I don't see it as really any better than other duty/service cartridges, from
.38/9mm to .45 ACP.
On the belt, in a holster, a G27 is not much more concealable than its larger brothers, at least on my body, the way I wore them. I just carried a G22 or G29 when using a belt rig, instead of the G27. I sold the G27 to a colleague, who already had one G27, and wanted to have a pair.
I hope this long-winded explanation is helpful.