Just dinged 55 a couple days ago on my Shield tech, and have been following the spec advice on Noxxic.
For the most part the talents they selected seem pretty reasonable, but I was puzzled by one thing: they recommend putting 2 points into Iron Fist (Pyotech tree) to increase damage from Rocket Punch by 8%. This is fine as far as it goes, but Rocket Punch is one ability and it has a 9s CD. There is a talent in the Shield tech tree (tier 2) called Hyper Fuel that with 2 points invested would give me 4% more damage on all fire effects, so at the very least this will boost Flame Burst/Flame Sweep (no CD, lowers damage from the target and snares for Flame Sweep) and Flamethrower (18s CD, but I have Flame Engine, which can finish the CD on this when triggered).
I find myself using all 3 of these abilities frequently, whereas Rocket Punch has the CD (though sometimes it gets reset by Hydraulic Shield), so is only used when it's available: I do try to use it as much as I can when in melee range. My sense is that 2 points in Hyper Fuel would be better than 2 points in Iron Fist, but I figured it's better to ask people with more experience since I am just starting out.
TIA for advice and pointers.