That reminds me, I need a new fid....I managed to lose mine last year! No big deal as it was simply a short lenght of 8mm copper domestic heating pipe cut off at an angle and the rags sanded down....just as usefull as a spike for splicing but being hollow you can push it through, slip the line inside and then withdraw both fid and line making the whole job less that bit quicker and easier!
As for strength of a splice, even a poorly formed splice will be at least as strong as the original rope and a well executed job will be many times stronger! I splice all my own winch ropes and I've never had a splicing (or ever known one) part yet.
Toddy, re finishing for a tidy job....I sometimes 'whip' the finals on splices for durabiity but it also tidies the job up nicely too, plus I find it's as satisfying to do as the splicing itself!