It does depend on the knife. Everyone knows I think Grylls is a knob BUT some of his signature knives aren't too bad.
They are all made by Fiskars / Gerber anyway.
His fixed blade "Ultimate" survival knife comes in different versions and are about 10-15% smaller than Gerber's LMF series and almost identical. They have a straight edge and straight / serrated edge versions (I have 1 of the latter) that can cut, chop, skin, strapped as a spear head, hammer and include a crap sharpening stone, flint stick and multi positional sheath which is actually pretty good.
Only thing it is a slightly thinner and shorter full tang blade and no glass breaker. It is also a bit cheaper than the LMF series as well.
As most would know that orange is the international distress colour which is why it was adopted by Grylls.
I also have Gerber's LMF 11 version which is far superior and also my preferred knife of choice for everything except using it as a paddle. Yes it does cost a bit more but you do get a better knife and also a strap cutter. This knife is now the chosen issued knife of the Australian SAS apart from those who choose to spend $340US on the Trakker knife (awesome bit of kit).
Some of the smaller Grylls knives are "OK" for most peoples needs.
What parts are you concerned about Tas?