Commercial fire alarm systems

[DKL]

Anyone familiar with/service these? Our local firm has been bought out and the newer, large outfit kindly did an "audit" of the system, no charge to us you understand, and surprise they have "found" a bundle of things they recommend upgrading.
The system is linked to the parent system of the landlord and I'm sure they would have been very keen to insist we change things had that actually been necessary so I'm keen to see what actually needs doing, I appreciate regs change and even for the better sometimes.
This however seems a complete business generator on the new companies part and I'm not playing.