Funnily enough I've just been recruited to join the VBM team at EY. My background is in valuations for tax purposes of shares, businesses and intellectual property along with the subsequent negotiations with HMRC to agree value, so I kind of slot straight into a 'gap' they have at present.
As I don't join until February I can't really speak specifically about EY, nor the business modelling side, however with tax valuations the work is typically undertaken in conjunction with a wider transaction. The work is very much 'short sharp projects' (typically 6 weeks long), although you'd probably be juggling two or three projects at the same time rather than working on a single project in isolation. Also, from experience,valuations isn't one of those departments that is organised like a pyramid with the junior grades doing all the work as the more experienced you are, the more complex work you'll undertake.
What really sold EY to me is the flexible approach to working. I thought it was a gimmick when first told about it however I've had a few conversations with the director whom I had my interview with and a couple of former colleagues that now work at EY. It's very much a case of getting the job done and that they don't clock watch but at the same time don't expect you to either. From this I understand that if something is urgent and you need to stay in the office till 9/10 o'clock then no one will have an issue with you appearing at 11 o'clock the next morning. Also I've managed to agree, as I'll be commuting a fair distance, that I can work from home two days a week. Home working seems like something very much accepted within EY as long as client commitments are met.