This race was special for me as it was my first marathon race. And so, I decided to go for the original one! ;)
It was a very tough race. form km 18 to km 31 there's a constant uphill, even that not too steep, but that makes you quite tired. The last 10 km are mostly downhill/flat but but by then you body cannot speed up.
Regardless, this was an amazing experience and I wouldn't change it a bit. Entering that stadium, with all the story behind, with so many people cheering you (there are people during the whole course) it's an unforgettable and amazing experience.

The aiding stations (after the 5th km there were drinking / feed stations every 2,5km), the volunteers and the management of every detail of the race (for example, they have to send the clothes bag from Marathon to Athens) was very very good.