It's awesome to finally get an upgrade pack with physical models of the relics available in the codex; it adds a really nice touch to actually see the relic on a model instead of just saying “This guy has X relic”.
However, I wish the box either came with more shoulderpads, or that they were available in a separate pack, like every other upgrade set.
Currently as it stands, every purchase of this upgrade sprue after the first is somewhat redundant: about half the pack is parts you would only use once across your army, so that would leave you with a plethora of half-used sprues if you bought multiple copies. Also, unlike other chapters, Black Templars wear their chapter symbol on both shoulders; 13 shoulderpads would easily let you convert a full squad of marines in any other chapter, but it's only enough to convert 6 Black Templars marines.
This wouldn't be so bad if the upgrade pack wasn't twice the price of any other space marine upgrade pack due to all the extra parts; $60 is a lot to spend on a dozen shoulderpads and a few tiny trinkets amd decorations.
Ultimately, I can highly recommend buying ONE of these packs if you're a Black Templars player, maybe two at a stretch, but any more than that feels like you're wasting money: at that point I would just suggest getting 3D prints of shoulederpads to continue conversions.