I have boght Helion 16 for my son, 3.5 yrs old 104cm height. Before He was riding Woom from 1.5yrs.
ER Helion 16 bike looks great. Fat tyres, acurate hydraulic breaks, as I can see, son hadels it well (from the second day:)).
What I did not like: it is china made!!! but seller declares that it is Swiss made. Tyres and brakes are some “no name”. The packedge was not so good as it was said in description. There is no instruction how to attach ligt reflectors. It coud be more protectors from the chain between the leg. There is no accesories in stock (like stand leg, and etc.) The bike front fork was scrached from the box paper. So in a conclusion I would say, that the bike is good, but is not so well served as discribed. Woom looks different, but I prefer quality of serving, packing full range of accesories and description. The price for ER shoud more friendlier. I do not think, that I will go for “ER full” bike, after my son will grow out this Helion and hope this bike still be in acondition to ride for my youngest son.
So this my experience.