This is certainly the most similar to the G1 cartoon model, for sure. Although in relative terms, T30 Springer is the most accurate to its source material (IDW Springer). Let's compare...
* In 1986 Springer was presumably co-developed by HasTak with Sunbow. The Marvel Comic model is based on an earlier design for Springer, the Sunbow model is a later refinement of that model, and the G1 toy is the final product. This toy was limited from being concurrently designed when TFTM was being produced plus, ya know, being the 80s.
* Siege Springer is clearly based on Sunbow Springer but we can see notable differences. It does a very good job in that when you look at the toy your brain immediately recognises it as Sunbow Springer.
* Thrilling 30 Springer is a near-perfect realisation of IDW Springer. It's almost as if Springer jumped out of the comic books and became a realboy^toy.
If I were to rate these 3 toys from most to least like their respective canonical models, I would go:
1. T30
2. Siege
3. G1