I have the G3.5 and its a fine tool for keeping up on the skills durring the non flying months, as well as working on those little things that are giving you trouble in real life flying,the nice thing as well has been the extra planes off the RFlight site.
I have downloaded at least 75 planes,or aircraft variants, that are not included in any of the software in the sim some of the designers do a great job with replicating the actual planes.
a sim is no substitute for real world practice,but I was really surprised how much better my flying skills had gotten by spending some time in front of the screen,mostly T.O. and landing,and crash recovery developing the instincts to rapidly adjust to bad situations and prevent,pile of sticks syndrome,as of late I have been doing more building than flying so the sim has helped keep the edge that leaves over time the price on G3.5 has gone down a bit and works well for my needs I see no need to uprgrade for another 200$ for a couple of lakes,bottom line is get the best you can afford,as long as you use it constructivly as a simulator not as a game console theres alot to be learned from a sim,thats why I have Playstation for playing games.