The Bill is very technical and repetitive (or consistent depending on your point of view) in how it deals with the various processes. It is not an easy or entertaining read but is relatively short. It is, very broad in its approach. Whether this approach will work is probably a question which will be answered with the benefit of hindsight in a few years time.
The Bill provides for the saving of EU derived legislation into domestic law, assisted by a new, but long, list of relevant definitions. It provides various powers to Ministers to make secondary legislation to deal with "deficiencies arising from withdrawal", to ensure compliance with international obligations and to enable "implementing the withdrawal agreement". These powers are subject to sunset clauses; meaning some can only be used before the "exit day" and others for up to two years after exit day.
Certain powers required to make secondary legislation can also be exercised by devolved authorities, in Scotland either by the Scottish Ministers or the Lord Advocate but only where they already have legislative competence. Other powers are to be exercised jointly or with the consent of the UK Ministers.
This has not gone down well with the devolved governments who argue this is a "power grab" and that anything already devolved, to any extent, should be coming directly to Scotland, even if others might suggest that is beyond the extent of the existing devolution settlements.
The UK Government say its approach reflects the current constitutional reality of devolution and, what moves later from Westminster to Holyrood, is a matter for further discussion.
Under the Sewel Convention, the devolved administrations can refuse to agree the terms of the Bill but legally this will not prevent the UK Government from carrying on regardless. However, much that would create a huge constitutional issue, politically.
The processes for exercising these powers are set out in extensive detail in the Schedules, but in short, this Bill is designed to enable UK and devolved Ministers to amend the law before and after exit day to make the legal system works on day one.
Powers of this kind are normally drafted to achieve specific outcomes to make a Bill work. Those instructing a Bill tell the draftsman what they want to achieve and then the draftsman makes sure the powers are wide enough to do everything expected.
In this case the UK Government have, not surprisingly, no clear idea whether this Bill will allow them to do all they need to because they have as yet no real idea of the outcome of the negotiations. This probably explains the breadth of the powers taken and the limited number of detailed examples of how they will be used.
Politicians scrutinising the legislation across the UK will have to trust in their own focussed scrutiny processes to hold their respective governments to account. There are bound to be issues. The volume of legislation which will be required to achieve the legislative side of the Brexit project is huge over and above the normal day job legislation to keep the country going. The majority of it will need to be completed before March 2019 which is a tall order.
This is just the first piece of legislation to allow the practicalities of Brexit to happen. Another nine or so topic specific Bills are expected. They may be even more difficult to draft given they are dependent on specific negotiation outcomes.
What is clear is that there is going to be a lot of midnight oil burned in Whitehall over the next year drafting legislation under this Bill, assuming it comes out as an Act on the other side of the Westminster machine in its current form, which itself is not guaranteed.