Thanks - its not mine btw - lol - but I reckon utube is pretty good for finding this sort of stuff you know -

Well - I think that's kinda his point though about 'You and Your sentry' where both of you are attacking, and it not just being the sentry only and you are busy 'tanking' instead. You will probably kill the solly and get your sentry destroyed, but YOU will still be alive, hopefully and be able to pick up his weapon and build another. I must admit its quite a weak gun, but it is very effective when you have several team mates in the area.

Maybe a lvl 2 sentry would be a better compromise between time/metal to build and damage it can withstand? He did, however, mention that if you cannot get any where - you ARE supposed to upgrade the sentry. Its probably only really an effective strategy for the cp maps and maybe in 2fort when you are building in their base (as long as there is already an engi who is defending the intel areas properly - we all know how annoying it is to have only one engi on the team who builds his stuff in the enemy sewers or sth, without any defense for the intel - )