PressCuts arrived.
Took the largest of the Tonic squares and matched it with the corresponding Presscut. Did one pass in the GC on same 300gsm card. No difference in the cut.
The outer edges of the Tonic dies are about a mm wider than the Presscut presumably to accommodate the little lining up notch they have. Tonic also come on a little magnetic sheet whereas the others don't.
All in all for a plain die I am very pleased especially at the price. I don't give a monkeys about magnetic sheets or the lining up notches, With my eyes I can barely see them anyway.
Just edited to say both Tonic and Presscut have narrower outer edges than Spellbinders.