Might be worth you keeping the tiered system as is, from a visual perspective, in the future. After all, not everyone's Mech is going to be upgraded and customized right start and there is a certain allure to a factory finish all of its own, at least to begin with at any rate. It's also worth noting that distinguishing between battle hardened combat vets who have been in the field for years, and the rooks who come in; might be worth it, again from a visual perspective, to make sure each stands out clearly from the other. I.E. "That guys a Tier 1 rookie, because his suit is basic looking. While this other guy has a lot of modifications and custom detailing on his, so he's most likely a tier 3 Vet" I also agree with whats been said by other deviants here in the comments about the armour. Having read your reply I can definitely see what you were going for with the armour on the tier 3 mech, However I do also agree with the idea of having the armour be a multilayered break away system. It would be visually very impressive if executed correctley as it's rarely seen in Mech designs at the moment, specifically more western designs such as those of the Mech warrior universe. Most tend to go for the Bolted on approach or making it part of the overall design/interior exo skeleton.
All in all and despite some small visual faults, this a pretty damn cool mech design, simple but without being plain or too 'Flat' and lifeless. If you decide to revisit the design, I for one can't way to see what you come up with next!
I was considering returning to the concept of modular upgrades sooner or later with a different design of mech. I admit to the visual flaws, I did these very early on with in my use of digital media and was fairly lazy. I'll keep those finer points at heart when i tackle the concept again. Big thanks for such an awesome and helpful comment
the visual flaws are only minor and easily overlooked by most, as they don't detract from the overall design you were going for and, have achieved in these tiered designs. As for the comment itself, it was my pleasure sir. Suffice to say that I don't normally go out of my way to comment on Deviantions, one word or one line replies feel kind of hollow. It's my personal opinion that if you going to say something, make sure it counts. Don't just put 'good, yay', that being said, that's simply my way of doing things!
I look forward to when you come back to this design or a similar setting are have another crack at it!