The three T's all have their strengths and weaknesses for me...
For cologne-type scents, I prefer T&H Grafton and TOBS Mr Taylor over the rest. Hon mention for T&H Trafalgar, though!
For florals, Trumper's Violet is a distant second to T&H Rose, which smells absolutely incredible to me. Everything else lags far behind, although I have yet to try the TOBS Lavender.
For the most moisturising, I prefer TOBS Almond or Trumper's Coconut. The much-loved TOBS Avocado hates my skin.
Value for money - Obviously TOBS wins as they all require similar amounts of cream to get the job done. They all lather pretty much the same for me, although the Taylor creams tend to vary in consistency and the runnier they are the better they lather for me. T&H are pretty dense and can be a bit fussy about water ratio in my experience, but when they lather, they do it exceptionally. None of the lather from any of these companies dry out on my face - you could be the slowest shaver in the world and still have whipped cream on your face towards the end of a pass.
Is there a difference in price and quality? Not enough to warrant the silly difference between T&H and Taylor, IMO. That said, although I may not always prefer them, I believe the T&H scents to be of slightly higher quality than the rest, and their quality control seems better/more consistent than the other two. Could just be my experience - who know how long that pot has been in a warehouse before it gets shipped to you?
Trying the majority of their output has left me with a zen-like ability to be without any of them in my shave den now. If I had to purchase one again to use forever, it'd probably be Mr Taylor, purely for the cost/scent. I do want to try the lavender first, though!