I tried Ancestry's Britain and Ireland collection a year ago, but cancelled within the 14 days without any problem.
If England and Wales census data is what you're after, its fine, but much of the rest is not what I'd expected. From the descriptions, you'd think they had actual source data, instead there are lots of indexes which refer to microfilmed data I have no easy access to. E.g. service records of the Royal Irish Constabulary.
The Parish and Probate records are likewise merely indexes, and of poor quality.
See as an example below, the result of a search for Archibald Douglas in Scotland.
West Lothian, & Midlothian; Gloucestershire: Edinburgh; Bristol- Commissariot Record of Edinburgh, Register of Testaments, 1514-1600; Bristol Wills, 1572-1792
This is the rol of the parish of Portpatrick above tuelve yeirs of age according to my knowleg and subt. be me Master John Calduell, minister throf this day of Oct 1684. M. J. Calduell.
The Commissarint Record of Edinburgh.
Register of Testaments. First Section--1514-1600. Edited by Francis J. Grant, W.S., Carrick Pursuivant of Arms.
County: Midlothian
Country: Scotland
Skeldie, Archibald, in Gogar. See Douglas, Margaret.
West Lothian, & Midlothian; Gloucestershire: Edinburgh; Bristol- Commissariot Record of Edinburgh, Register of Testaments, 1514-1600; Bristol Wills, 1572-1792
This is the rol of the parish of Portpatrick above tuelve yeirs of age according to my knowleg and subt. be me Master John Calduell, minister throf this day of Oct 1684. M. J. Calduell.
The Commissarint Record of Edinburgh.
Register of Testaments. First Section--1514-1600. Edited by Francis J. Grant, W.S., Carrick Pursuivant of Arms.
County: Midlothian
Country: Scotland
Douglas, Archibald, sometime constable of the Castle of Edinburgh 15 Aug 1590
Midlothan: Edinburgh - Roll of Edinburgh Burgesses and Guild Brethren 1701-1760, (Abercromby-Hepburn) and (Stevenson-Yuill)
1837.
Roll of Edinburgh Burgesses, 1701-1760.
On Top.
County: Midlothia
Country: Scotland
Campbell, Wm., servant to Archd. Douglas of Cavers, B., gratis 15 Apr 1719
Midlothian: Edinburgh - Register of Apprenticies, 1756-1800
Volume 5. The Register of Marriages.
Register of Edinburgh Apprentices 1756-1800
Addenda et Corrigenda.
County: Midlothia
Country: Scotland
Douglas, Archibald, s. of James, shoemaker in Dunkeld, to James Clark, shoemaker, for 6 years 12 Apr 1792
Midlothan: Edinburgh - Roll of Edinburgh Burgesses and Guild Brethren 1701-1760, (Abercromby-Hepburn) and (Stevenson-Yuill)
1837.
Roll of Edinburgh Burgesses, 1701-1760.
On Top.
County: Midlothia
Country: Scotland
Douglas, Alexr., hatmaker, B., be r. of umq. fr. Archd. D., armourer, B. 10 Mar 1708