What should I look out for when comparing quotes?

Seven points, with the difference between the second pillar (collective) and the third pillar (individual) recurring throughout:

Costs. Compare management fees on capital, fixed costs per participant and any entry, exit or advisory costs. Are they included or added on top?
Tax treatment. Second pillar: premium from gross salary, benefit taxed as income. Third pillar: deductible within jaarruimte, capital outside box 3 during accrual.
Risk sharing. Collective schemes share risk and sometimes offer guarantees; in individual schemes the participant carries all risk.
Flexibility. Who takes part, how much, and how easily can you change it?
Administration. Consider reporting obligations, governance structure and the load on your payroll.
Communication. Do participants get a UPO, a dashboard, or both? And how is choice guidance arranged?
Portability. Do entitlements stay behind on leaving, or does the personal pot move with the employee?