Has anyone here actually used a UK-based PEO?

I’ve recently started exploring international expansion options for our small tech startup, and the concept of PEOs in the UK came up. From what I understand, they can help manage HR, payroll, and compliance without needing to set up a local entity. Sounds promising, but I’m still not entirely clear on how a UK PEO compares to setting up a subsidiary from scratch. Has anyone here actually used a UK-based PEO? What are the practical pros and cons you've experienced?