Wow, how time flies, it doesn't seem that long ago since we were offering congratulations and now your maternity leave will soon be over.
I did my assessor training (I'm guessing you mean NVQ) over 10 yrs ago so can't share current experience. The then pro's and cons of assessing were;
cons;
Not enough allocated hours to do assessments.
Lots of paperwork
lots of candidate support to understand the 'jargon' of NVQ
Ambiguity in terms of level of knowledge and skills required of the candidate re: IV (internal verification)
my expectations were higher than fellow assessors (so caused moderation type queries)
My main grievance with NVQ is that it is supposed to be reflective, about embeded knowledge and skills yet in practice a candidate will have a training session one week and be expected to 'perform' on this learning the following week. It is 'bums on seats' funded and not as accecable to 'vocational practitioners as the 'spin' suggests due to te high excent of written and portfolio building work that is required of the candidate. I personally don't agree that candidates should go straight from level 2 to level 3 without some time given for consolodation.
Another difficulty is that candidates can be held back by the 'quality' of the setting they are working in, the support, or lack of, from employers.
Pro's;
Enabling / supporting candidates through a learning experience
seeing candidates progress and achievement of qualification
Varied settings, seeing how others work.
freedom to plan own work schedule.
pay above minimum wage
sense of driving forward quality
enables self to keep up to date with current practice.
providing workshops
Good supportive employers who offer a quality environment for candidates to work, learn and draw evidence from.
Good luck, let us know how you get on if you decide to follow this career path.
Peggy
p.s. just realised I've described pro's and cons of assessing rather than the training for assessing

My training was through a LA project, short time scale, completed portfolio which was lost by the college so my main advice during training would be to KEEP PHOTOCOPIES AND BACK UP OF EVERY PIECE OF WORK YOU DO.