These binders are both beautiful though, apart from both being A5, quite different.
The Gillio Mia Cara is bigger (due to the outer ‘sleeve’), made of heavier, grained, leather and has gold 30mm rings. The Van Der Spek A5 is regular A5 size, made of lighter, smooth leather and has gold 35mm rings.
I would prefer each of these in different situations.
For carrying with me I would definitely prefer the Van Der Spek. Lighter, more compact and yet capable of carrying a huge amount of paper in those unusually large rings.
For using at home, I would prefer the Mia Cara due to the full length wallet pocket across the back which is hard to do without once you get used to it.
It is hard to compare price because they are rather different binders. The Mia Cara is made of a lot of leather so that definitely is reflected in the much higher price.
If you are harking back to the golden age of Filofax, the Van Der Spek is really evocative of that era. When I first saw it, it transported me straight back to the 80s and 90s (in a good way), which is not surprising as it is from 1994/5.
Price-wise you cannot ignore the fact that the VDS would go for €180 but the Gillio is €610