It kind of depends on what you are wanting/needing out of the light I guess. With the PD35 Tac you have about the same run time as the TC15 when used on High mode.
The TC15 is aimed more at an everyday carry where the PD35 is aimed a little more at Tactical use.

There are so many lights out there now days that have the same basic design with many of them having pretty much the same features also. Many times it comes down to the personal preferences of the individual buying the light and then more so the price point of the light.
Both of these lights come with Included cell and are USB rechargeable and all the same accessories , so if I was looking to purchase a light of this type , I personally would start asking myself a few questions if trying to decide between the 2 and did not already have one or the other…….

1. Do I want or need the tail switch that the Fenix has or is a single side switch enough for what I use the light for?

2. Do I need the extra brightness at times of the TC15 with double the lumens or no? (even if only short burst)

3.Which light is more appealing in the overall features and/or UI for my personal use?

4. If used as an EDC light and features of 1 or the other lights are not at the top of the list , would I rather pay the $49.95 for the TC15 or the $71.00 for the Fenix.

I am sure they are both good lights with the build quality being there , as I have a couple of Fenix lights and around 14 Thrunite lights and I don’t have any complaints about the build quality of either brand from what I have seen.
So again I am sure it will be what the buyer is wanting to spend and the personal uses and preferences that would be the deciding factor in the end.