Instead of their tin whistle?
Juuuust wondering!
Cheers and Happy New Years!
Armand
I only occasionally play my low, actually.
I primarily play my low whistles. I currently have low G, F, D, C and Bass A that I play.
I play my low whistles almost exclusively now. My Hoover and Overton low D’s get most of the playing time, but I also play the low E, F, and G. About the only high whistle that gets much playing time is a Hoover Bb.
I play my D and Eb whistles most of the time. I prefer the sound of a high whistle and I don’t have the lung power for low whistle. I have enough different whistles in D that I can pick a sound to fit my mood.
Ron
All low, all the time. 
From a low G down to a Bass A, and working with a Bingamon D Basswhistle (1 octave below a low D), I stay at the bottom end of the whistle world. I do play the higher ones, but the type of music I’m most into calls for the lower voices.
Cal
I also primarily play low whistles, my Overton and Copeland low Ds.
Deb
Depends who I am playing with I pretty much only use the high whistle for sessions. 
Thats all I play although I do play several soprano’s. I focus most of my playing on my Chieftain Gold Low F, but do have Chieftain Lows in A, Bb,D,Eb,G.
I play a lot of low, but usually whatever suits the tune I’m playing at the time. Sometimes a low(er) whistle will spice up a tune I’ve always played on my high D even more than trying to vary the bejesus out of it (I do think though that my new high D I just got is the finest I’ve ever played and have indeed been playing it a lot lately!). In short, whatever suits the music - exploring different keys, especially what would be considered ‘exotic’ in the IrTrad world, is a lot of fun!
Yes, lows are where it’s at for me. Occasionally I will pick up a higher voiced whistle, but it just doesn’t reach my soul like the lows.
I can appreciate a well played high whistle, on a great tune though. But I would still prefer to hear a slow air on a low whistle or flute first.
Unless I am in a Mary Bergin mood, I play the Low D.
With my old Chieftain, I used to play my low about 5-10% of the time. It just couldn’t handle the faster tunes. With my new range Chieftain, I play the low about 70% of the time at home. At session, I still only play the low maybe 15% of the time.
Never owned one..always been into GenD,Eb and F.
Reels,Jigs and Hornpipes. Up high,dipping and swooping around the place.Great.
Ebs a great key for airs.
Always felt that for all the Soul in Low Whistles,there’s no Spirit.
Slan,
D.
Since I’m learning new tunes and improving old ones with my teacher, I almost exclusively play a soprano D, and almost exclusively my Burke black tip. Maybe once a week I’ll pick up the Burke Viper Low D and my Copeland G (just to hear that inspirational voice).
Philo
I spend a lot of time with low G and F; less with D. I usually play low Eb or C only when a particular tune calls for it.
For dance music, I mainly play high D and Eb. I tend to play some high and some low most days.
I ony started whistling two months ago, at 65, and was only interested in a low whistle…got the overtyon low D to learn on…real hard work…have since bought a Chieftan F and love both whistles…but…in my search for a really good sounding high D have just started searching for a wooden one. So early on, and still learning but I have the bug.Do love the low whistle sound though.Les.
Les Cruttenden all I can say is that inspirational to me, to start at 65 is great.
Is it incorrect to call a low whistle a tin whistle too?
Anyway, no, I primarily play my little tin whistle because the low one is harder on my tiny hands. 
i would say nobody would use the term tinwhistle for a low whistle, but, however, it isn’t incorrect (in my opinion) to use that term for low whistles as well.
Me, i practically only play my low whistles now.