Yep, I was also very disappointed when I saw that. A 'pet' which disappears after 4 hours? This is ridiculous. Make it cost 750 Romulan marks and 30.000 dilithium for all I care, but make it a permanent vanity item!
That's really disappointing... and I was planning on getting both sets.
If it's a vanity item, why give it a timer at all?
And speaking of vanity items, I was extremely disappointed about the time limit on personal holoprojectors too. So much for buying a Jem'Hadar First and a Breen one. I can see you giving it a cooldown if, say, the Borg drone one let you slip past other drones in ground STFs... but they're not even functional in combat.
Won't bother getting them. Way to make us feel rewarded for hitting T5. Bad form, sirs.