Front = mini
Back = angel
Angels are complex by design but when they work they are good just when they play up you spend a lot of time fixiing them
Why is an angel a back players gun, are you saying its got more range and accuracy and shoots more paint. If so you're probably right on all counts.
I've not only shot, but owned both, I was seriously impressed by the Mini, but I would say that it is more complicated and fiddly to work in than the Angel. All guns have wear items, some are easier to see than others, on the Mini you'll need to change the o-rings on the bolt assembly, and lube it DOW 33 after each day's play. On the speed you need to put a couple of drops of oil through it every now and then.
If it is in good order and set-up well an 05 Speed will serve well, though set-up is important, they were pretty harsh out of the box and needed running in, then with the ram and pressures set right they will run perfectly for ages before needing attention. Though it is worth getting someone who really knows what they are doing to set it up right.
Like TheGurkha says, flick a switch and its on, flick it again and its off, Squaddie proof maybe, but I wouldn't say they were idiot proof, idiots take things they don't understand apart and screw them up.
The Mini I found pretty horrible out of the box, the trigger settings were horrid and it was well inconsistent over the chrono, after dry firing a couple of tank fulls of air through it and putting a bag of paint through it and re-lubing the bolt assembly it shot much better.
Personally I passed the Mini on, preferring my Angel One to it, though I thought it was an excellent gun for its price point, and the Speed is pretty much retired now, though earlier in the season it was still keeping other people in the game while their guns refused to work.
Hope that helps, both have their merits and you really should try if you can before you decide.