Like many metal guns such as CZ and Beretta, I love the soft recoil and accuracy of Sig P Series Sig's and the 239 is one of my favorites. The 239 fits a spot where it is 8 ounces lighter than its bigger brothers and much easier to conceal while carrying. It inherits the same shooting characteristics of the larger 229, 220 & 226 while possessing a slimmer grip profile. Surprisingly, loaded it is only a 3 ounces heavier than my .45 Shield and yes, it is roughly the same size at a G19 with with the exception of the grip, and that is what mostly prints when carrying. Yes, its a single stack that hold 8+1, however that is offset due to how slim the mags are and the ease it is to carry extras. I usually use a mag carrier but if I slip a SS mag in my pocket I will not normally know if its there, however I would know if I have either a G26, G19/G23 or G30 mag in a pocket, not it mention the larger 17 round mags.
Regarding my SS list, the 239 is definitely in my rotation and a favorite for many reasons. Loaded my P239 tac weighs 32.7 ounces and as mentioned previously my Shield .45 weighs about 29 ounces so yes it is heavier but hardly as much as some make it sound. I love my G43 with overwatch precision trigger & Trijicon HD's, my Shield .45 &, 9 w/apex duty kit, and 8 various glocks with NS & apex triggers yadda yadda, however my 239 tactical is among my favorite and will see as much holster time as any of my others; it all depends what I'm doing or wearing for what I have holstered. If you like P series Sigs you will like the 239, so I wouldn't be discouraged by what others say as only you will know if you like it or not.
For me, I find my FS 226 & 220 a little on the big side for carrying as they print more that I care for but find 239 ideal as it much much lighter and conceals nicely, much better than the FS Sigs and even less than my G19/23/30 . According to my scale my FS Sig's weigh in at about 40 to 41 ounces loaded so as a mentioned the 239 is much lighter by 8 ounces.
Lastly everyone is vastly different so take what everyone says even myself in stride and make up your own mind, however like I said if you like the full size Sig's you will like the 239.