used to play this in rs1...had a level 50 something with full rune plate and lots of gold...then they updated to rs2 with different leveling systems and the whole thing was different and me and all my friends, and most of the high levelers quit. Well i was like 14 at the time lol. I tried to start again and I think this game sucks and has always sucked.
The buildings are useful and I find them impossible to defend in the 40k range without using them at the same time.
For those who want to take advantage of the buildings my strategy was to upgrade the flak and shield first, and the emp comes later when there are hordes of missiles coming in...the time slow only saved my ass when I upgraded it to level 3 or 4. I find the time slow the most useless and the flak most crucial. Use your shield siphon to keep recharging your flak so it never runs out..