I don't have any experience with the TSX but I can tell you that the 250 gr AB from my 338 RUM has never disappointed. I've always had ample expansion, even through the slats both near and far.
Hope this helps.
I have had great results with the TTSX bullets in multiple calibers on whitetail. The only TSX bullets I have loaded now are the 500gr. , but no deer has stepped out and tried one. Make sure the tip is open and you should be fine.
I loaded some 160 grain TTSX bullets for my .338 Win Mag but have not had an opportunity to shoot them. I think the key to bullet expansion with TTSX and TSX bullets is high impact velocity. I would imagine the 180's would do a great job on whitetail.
What speed do you get with them?
I used the 168 TTSX in a 30-06 way back on our small roe deer.
Looking back I should have taken the 150 gr variant.
But still, they usually went down quickly and expanded. You white tails are way bigger and I don't expect them to pencil through on reasonable distances.
Within reasonable distances, the TTSX will open without having to hit the shoulder.
At closer distances,you might loose a petal or two, if you hit hard bone with that speed. These might take a strange path and ruin a bit more meat.