I think you have answered you own question.
I try as much as possible not to use the fence on the Makita. There's nothing wrong with it, but using the baseplate avoids my own mis-setting mistakes. On the occasions I have needed it, it's been spot-on and hasn't let me down.
It matters if the blade is parallel to the base, and it sounds like yours is.
I doubt that any manufacturer actually intends to make a tool shoddily, but some are a lot more cost-of-materials conscious than others (also cost of tooling and time in production). With the cheap stuff you _might_ get a good one, or perhaps not. One thing you are paying for in more expensive brands is consistent quality.
In biscuit jointers there is definitely a race to the bottom now, as most of the significant patents have expired. I've seen many "brands" of the same tool, presumably from the same Chinese factory. Unlike the copies of the Elu routers, you don't see several quality brands using essentially the same production line - the biscuit jointers are cloned at the low end of the market instead, as it seems to be becoming a volume (rather than value) business.
When the latest Makita came out, I wondered what they could possibly have done to improve on mine. Answer: nothing - as far as I can tell the latest one is a cost-reduction exercise. I imagine Makita thought they were being stranded in the middle of the price range - too cheap to be chosen by the quality-above-everything fraternity (who would go Mafell, Lamello, etc.), and too expensive to sell in big volumes.
There's still nothing obvious wrong with my earlier Makita model. It _is_ a quality tool (the build and finish on it are excellent), and I would guess it performs pretty close to a Lamello, but at around half the price when I bought it.
But people tend to shop by reputation or happenstance or price - it is relatively unusual for mid-low end purchasers to take the time and effort to try a range of items first (and anyway, cheap tools are not sold that way). We rarely make considered decisions as objectively as possible, and the manufacturers know that. Their first priority, _always_ is to make a profit and stay in business. As markets change they have to adapt.
It's similar to drills and other power tools: I think sticking batteries on everything remotely portable is expensive and wasteful, very bad for the environment (battery tools are horribly energy-inefficient and the batteries themselves are about as eco-friendly as an oil slick), and gives you a sub-optimal design in most applications, but Lithium-ion battery-powered tools are what the majority of purchasers with dosh now want to buy.
So, very soon I will be unable to choose from a range of corded tools - it will be battery-powered or a very limited selection of either really, really cheap corded (or niche high-end stuff).
Meanwhile, back at your biscuiter - the short answer is you would gain very little from swapping to something expensive, probably. If your work relies on being able to plant biscuit slots accurately , many times per day, every day, you'd appreciate the difference, not least in reliability.
It sounds to me, though, that you're using your biscuiter in the work pattern it was intended for. You don't care about the quality differences with more expensive models, and the manufacturer correctly predicted that.
Yours isn't a "wrong" choice either, in my view, just not the one I would make.
E.