Money aside, on a daily basis how enjoyable is the Job?
Even if you're a big introvert and like your own company, the solidarity lifestyle of the job might be difficult at times; that you're not interacting with many people.
Depends on the individual.
As a driver you will be spending long periods working alone, but the flip side of the coin is you'll be interacting with people when booking on and in the messroom, and at times during driving turns too - for example signaller, station staff, perhaps even passengers occasionally!
I'd say the bigger issue with the job is shiftwork and its consequences for lifestyle. Having to set the alarm clock for a time like 02:30 would be a rude awakening for many people, there are a good proportion of people for whom the only time they ever get up at that sort of time is to get to the airport for the annual holiday (the type of people who turn up on an early-morning train and **** off all the regulars who are trying to sleep by making a noise!). Shiftwork also can have a major effect on social life - you'll find yourself having to decline a lot of social invites, and eventually the invites stop coming because of this. However, the flip side of the coin is you get days off in the week which personally I find absolutely priceless, and most of the time can avoid peak-time travel which is also a benefit.
Lastly, the industry can be extremely political at times, and the driving grade certainly isn't immune from this. Although it's possible to try and "come in, do my turn and go home", there are still times when it's hard to avoid being sucked into depot/company politics, which can be infuriating at times.
All in all, I'd say there are far more positives than negatives, but if you're the kind of person who is likely to be adversely affected by the negatives listed above then I'd say the job may not be for you. Needless to say, on top of this, temperament is very important - the ideal person is one who is disciplined and takes safety seriously, but not to the point of being permanently uptight.