scrutinised by a lawyer and don't let your lawyers exclude that scrutiny from their terms. If you discover onerous but well hidden charges you want some redress.
Be especially careful of anything built in the last 20 years and completely avoid anyone talking of informal lease extensions on nearly exhausted leases i.e. "don't worry that the lease on the property* is only 40 years because the freeholder has agreed to an informal extension to 125." - It's a scam.
*the ghastly dickensian grotesque from the estate agent will pronounce it "prippertay".