The Garmin chest strap can well adapt to the body size, even if this is not so very narrow. The belt consists of a textile material, the actual sensor of a not particularly breathable plastic. On longer trips by bike you sweat pretty powerful under the belt.
The coupling with the Garmin Oregon 450 was quick and straightforward. In Oregon invoke the appropriate menu item and even the heart rate monitor is detected.
It is regrettable that the Garmin heart rate monitor is not compatible to the devices of Polar. The Polar devices can now with many devices from other manufacturers in the "Muckibude" are synchronized with the Garmin chest strap is the (in Muckibude my confidence) not possible. Therefore, a point deduction in the assessment.
Edit on 04/07/2014: In the meantime, I also use the just-released Garmin Vivofit bracelet. Even to this the chest strap is compatible and fairly easy to couple with the Vivofit.