I'm very mixed on this craft. If it were an older design, it could stand to reason the flaws. But as a modern design it has a stack full of flaws.
Spheroid: On the surface, this is a good thing. Unfortunately the lack of Aft Side weapons means it has blind spots. Smaller than aerodynes, but still unnecessary.
Weapons: The nose is packed with firepower. Then again, it's spread out between short and long range. The side firepower is strictly short range. Combined with no aft side weapons it means anything with long range guns can park off at range and pummel the Merlin. The aft guns are more an annoyance than a threat to anything but light fighters.
Armor: You can hold off against a medium squadron for a short while, but against a heavy squadron or most assault DropShips, it will crumple quickly.
Speed: One of the few saving graces. It has more thrust than most heavy fighters and heavy assault DropShips. It isn't enough to avoid assaults by medium fighters and fast assaults like the Avenger and Achilles. And with those short ranged side arcs, even a Seydlitz squadron could be a fatal threat to a Merlin.
Overall I'd give it a 4/10 score. In the Star League it would be worth a use, but in modern times it needs heavy support to be viable.