Actually, IMO you (and others) are totally off-base with your assessment/expectation of what the T10D should be capable. You are also completely wrong about me not having flown one as well, yes - I have other ships in my collection and often prefer flying them for personal reasons BUT that is besides the point.
As for 1k being a respectable amount of shielding - it is for PvE - certainly good enough for most free roaming encounters. This I know from personal experience flying it and other vessels. For PvP, things may be somewhat different but that is another story entirely (
all bets are off in such a case) - anything substantially higher than 1k is pretty much OP for PvE - especially after taking into account engineering for resistance. The only consideration where significantly greater than 1k on the larger ships may be desirable IME is for landing on higher G worlds - even then a good pilot may find even no-shields not an issue in such a landing case.
Also, If you look at the timing of it's introduction in terms of universe time and the general description, it was clearly intended to be a short term answer to an immediate perceived problem. The long-term answer being the range of Alliance ships as I pointed out in my thread and you have summarily ignored.
T10D description from INARA:
https://inara.cz/galaxy-shipyard/66/ said:
The Type-10 Defender is the result of collaboration between the Alliance and Lakon Spaceways. With the threat of xeno-war looming, the Alliance's naval arm saw the urgent need for a weapons platform capable of withstanding heavy, sustained attack. Utilising a reinforced Type-9 chassis as a starting point, Lakon overhauled and geared every aspect of the design for combat, producing a military behemoth that could be produced in volume at short notice.
This used to be in-line with the in-game description which has since changed:
But ultimately, the gist of it is really no different on balance. The current in-game description is in-line with the current ship capabilities.
As for me calling it a "mobile weapons platform", you really need to learn what that means before spouting off and claiming the individual in question does not know what they are talking about. While the T10D is not particularly quick or manoeuvrable (neither is a requirement for the term I used) it is more than adequate IME.
As for the PD, how limiting it is depends on loadout choices. Originally it was released with a weaker C6 PD but this was latter increased by one level to C7. As for weapon placement, a lot depends on what weapons you fit - if you are talking about fixed/gimballed weapons then you perhaps have a point (convergence of the L hard points is not good) BUT use turreted weapons and the situation is somewhat different - especially when you consider using multi-crew.
As for my comparison with other ships in the game, it becomes quite relevant when you consider the fact that (a) the T10D does not have a Huge mounting point (which can be a game changer in big ship encounters due to differences in hull hardness) and (b) the experimental/guardian weapons started out as almost exclusively being Large mounting point based in the beginning - i.e. when the T10D was originally released.
Regardless of which of the big 4 I happen to be flying at the time, I have found them all capable of dealing with similar sized (and smaller) PvE human threats.