I work for in Ops for the Rates (i.e. Govt bonds) sales & trading business of a large IB in London. It can be very lucrative, but it really depends on what desk you are on (and how good you are). In general the more liquid the instrument you are trading the less lucrative it is.
The top dogs (VP and above) rarely do more than 7.30 - 5.30. Associates and below are looking at longer hours, but this again depends on what desk you are on. If you are market making Govt bonds, then there is not much reason to be in work after the market closes (and most aren't). If you are a hardcore quant exotics trader, then the market hours have little relevance to you, and as such you have more leeway.
In terms of $$, the top traders make between $10-80 million profit for the bank a year. They will get somewhere between 6-12% of this as a bonus depending on various factors (i.e. how easy it is to make money in that market). Most will be on a basic of around $200k. An average trader will be making around $5m profit, and again will get about 10% bonus. A fresh out of Business School MBA grad will doing well if they make in the region of $1-2m profit.
In terms of MO jobs, Operations, and Technology (writing spreadsheets etc) hours are similar but the pay isn't

. A fresh out of undergrad MO / Ops hire starts on $70k. An Associate (which most decent ugrads attain after 3yrs ish) will be on 100k. Senior Associate / team leader / low rank manager will be on 120-150k ish. At VP / manager level you are looking at around 180k - 250k. Above VP level you have Exec Directors and MD's. There are almost no non front office MD's, but the ED's are probably on around 300k.