My experience (in a single campaign using the Gearmaster optional rules) was that having the skill limitation as a requirement seemed unnecessary. Players were mostly buying higher quality gear (and I capped it at exceptional quality for now) to augment skills they were already pretty good at, exceeding their MDP to perform more heroic feats or overcome tougher obstacles. The rule change is fine, I think. This idea from dekrass's post above sums it up well:
I like the idea of the untrained character benefiting from high quality gear. Sensors so advanced they practically run themselves, for example.
As for why I adjusted the rules from one armor class to the other... This game is heavily skewed against heavy armor. SOAK pen is easy to obtain and heavy armor is excessively expensive for the SOAK it provides. I wanted to actually reward a person for investing in armor that the core rules doesn't seem to value.
As an example using only the basic armor provided in the core book and ignoring the EONS post of extra armor (which doesn't help the situation), let's compare two suits of armor.
1) A standard battlesuit costs 2000cr and provides 8 soak with a vulnerability to electric damage. You take a -4 hit to your defense penalty.
2) A standard leather armor costs 35cr and provides 4 soak without any vulnerability. You do not take any defense penalties.
Paying 1965 extra credits for 4 soak that can be ignored by certain attacks and makes you more likely to be hit by any attack seems silly. Especially when an AP round from the standard ruleset will ignore 60% of your SOAK anyways.
It gets sillier when you consider item quality.
Keeping the comparison with a standard quality battlesuit... Player A has gotten this for 2000cr and is feeling beefy.
Player B decides to indulge in a mastercraft suit of leather armor. The mastercraft multiplier is x10 then +500 (base cost = 35cr -> 850cr) and gives +6 SOAK. So for 850 credits, he now has a piece of armor that provides 4+6=10 SOAK without any vulnerabilities or defense penalties. If you cap this at exceptional, it is still 5*35+250=425cr for 8 SOAK.
And given the multiplicative cost of improving quality, a HQ battlesuit is even more expensive for marginal gains in SOAK.
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As a side note: I'm experimenting now with straight-up doubling all heavy armor SOAK values as provided in the manual. It does present situations where characters can have SOAK in the high teens or low 20s, but I think that's a reasonable tradeoff.
Additionally, if you suggest being stricter with higher quality items, only providing them in uncommon circumstances, I'd counter with this question: if not better items, what exactly are players earning credits for? How are they incrementally improving themselves?