It's not a perfect ship, but none of its flaws are as huge as the Artemis's inability to dogfight well or the Zeus's poor armor and payload.
The Artemis supposedly superior missile capacity to the Zeus deserves to be taken with a grain of salt. When you consider the Artemis' unfortunate design, you realize that in those admittedly larger missile bays you have to accommodate both anti-fighter missiles and anti-turret ones. This leaves you, in a best case scenario, with room for 4 Cyclops.
The Zeus has smaller secondary bays, but with split primary systems and better placed gunpoints it can either carry a Maxim or a second anti-fighter cannon, freeing up a secondary slot to accommodate another bank of Cyclops. You can easily end up with 6 Cyclops there, giving you an extra 50% of raw anti-capital firepower when compared to the "superior" Artemis. Also, the fact that they are split in two separate banks means that, at least in theory, you can fire 4 Cyclops in a single pass (yeah, good luck with that).
Of course, a Maxim may not really be the same as a fire-and-forget Trebuchet or the slightly inferior Stiletto II for anti-turret work, and another pair of primaries in a bomber is not necessarily better than a dedicated missile bay for fighter suppression*, but in terms of raw firepower against capital ships the two are still comparable. It says a lot about an allegedly dated design when it can be at least as good, if not actually better, than its supposedly superior replacement in its more defining aspect (number of bombs you can put on the target before needing to rearm).
These same liabilities of the Artemis don't apply to the Sekhmet because it's far more prepared to deal with enemy fighters by using its primaries, while also having TWICE the missile capacity of the Zeus.
*: But do keep in mind that unlike the Zeus the Artemis is unable to carry Harpoons, which are the prime anti-fighter missiles.