Here are some pics to give you an idea how the E5 compares to other helis.
This pic shows a T-Rex 550 v1 next to the E5
These 2 pics show from left to right: Goblin 570, T-Rex 550 v1, and Synergy E5.
This pic shows the Goblin 570 (bottom) next to the Synergy E5. I lined up the helis at the main shaft. The Goblin 570 has a longer tail, but the E5 has a longer canopy. A larger canopy can accommodate electronics and wires more easily.
This pic has the T-Rex 550 and the E5 lined up at the main shaft. The E5 is longer than the T-Rex 550 on both ends.
Another pic comparing the Goblin 570, T-Rex 550, and Synergy E5.
I sold the T-Rex 550 and the Goblin 570 air frame and kept the E5 as my workhorse heli. The Synergy E5 overall has much better quality components than either of the other two helis.