I agree with those positives and negatives, all from experience. I actually prefer PET to TPU, but wanted the protection of glass. I put glass first, then PET on top, and it works very well with the s-pen. It's very hard to get precise control on glass alone with the pen.
And the Spigen glass is very expensive, considering it's the same as any other glass that costs half the price. Unless you really, really need the alignment tool, I wholeheartedly recommend the Supershieldz that bought. Here's the links: