Other thing to think about is that except for Fire your really not missing much and the Tables can be a pain in the **** due to crowding. So much so that I like never go there. Only other elemental plane I have heard of anyone experiencing in is Earth but that I think has gone way of the DoDo with all the expansions and zones since then to play in. Before OoW, DoN, DoD it was like the MPG exp area but now its not even close and your better off actually being in MPG or if high enough RSS.
I say take the time key and dont look back you really arent missing much except hours and hours of progression. A lot of the thrill on these encounters is gone now too most of the people who flagged me were like oh yay another trip to X. Except for a few rare items too most of the drops off these guys til you get to Elemental area are easily gotten for less effort in the bazaar or by killin th mobs yourself in OoW, DoN, DoD.
I would say get time key 85 if possible run Tipt work on your GoD progression. If you are short the numbers to 85 enough of your guild to time to make it so that you just kill there and ignore the other planes then you might enjoy it provided you have the numbers to pull off these kills and arent boring the hell out of your higher members. Some of em are a real Pita like Coraiv and Xegony and probably still would require multiple groups from the more elite guilds. Not like the 10 or so they took on their first few tries on em but more then 1.
I know WAY more then you asked but =P