I have many of each. Both are good options.
Buy the same size for each model (since it is Barrie, go 1/2 size down from TTS).
The PTB will fit slightly more snug.
I did. I have a few other pairs of shell on the barrie, all bluchers, and all a half size down. I initially ordered the J. Crew 8 boot in the same size as my bluchers and they were tight. I then ordered my true size to compare the two and the latter fit much better. I returned the first order and have been happy with the true to size fit half way through the break-in method.
I'm an 11D on the brannock with a slightly high volume foot. 10.5D on most barrie shoes works great but I had to go up to 11D on the J. Crew cap toe boot. Glad I had the opportunity to buy in store and try on both as I would have likely gone 1/2 size down if I ordered online.