Looking to buy a CFM. Debating between the Zforce 800 and 500 trails. I won't be doing major hill climbs and not to concerned about top speed, will the 500 go anywhere the 800 will?

[2015 Z Force 800 53/Trail EPS]

Do yourself a favor and just do the 800 cause like my late Father always said " it's always better to have and not need.. then to need...and not have". Besides, the 800s have been around longer. I have an 800 and most certainly wouldn't want any less.

^^ What he said ! I was recently in the market for a new daily driver, and after suffering through over 10 years of towing with a V6, I vowed I would not make that mistake again. Brought home a Hemi SUV, and while the gas mileage is as bad as I expected, I no longer worry about towing. With a 7 mile round trip to work, the low gas mileage isn't as important to me. My V6 could barely pull a hill without sounding like it was going to throw a rod.
Same with the choice of an 800 over a 500 -  the 500 can probably do most of what the 800 can do, but it always sounds like its being worked to death to do that, whereas the 800 does it with very little fanfare or commotion.

What they said!!!

My son-in-law and I were looking at the 800's & 500's in both the UForce & ZForce just about an hour ago.  We noticed that for both vehicles, the cost difference was only right at $1500.  For that difference, it's worth getting the 800's.

[2015 Z Force 800 53/Trail EPS]

My son-in-law and I were looking at the 800's & 500's in both the UForce & ZForce just about an hour ago.  We noticed that for both vehicles, the cost difference was only right at $1500.  For that difference, it's worth getting the 800's.

YES...absolutely.  (IMO)

I just went though this recently.   I came from a group of friends that rode lifted golf carts for years on the trails and back roads until this year when everyone started replacing them with ATVs.  Found out quickly that a golf cart cannot go through the same trails and keep up with the ATV guys.  I really was not interested in spending the big bucks on a loaded up Arctic Cat or Polaris ....  so started doing my deep dive research into the CFMOTO Z500 / 800.   Asked the same question you have multiple times on multiple forums and my dealer and basically got the same response you have received.

I was lucky to be in the area of a great dealer (Emerson@Harrison Power Sports in Michigan), this was more of a priority for me than the price as you will have some type of issue sooner or later (with any ATV) and I wanted to make sure the shop was more than capable of fixing them.    In the end I decided on the Z500 and have not regretted it so far.  You have to look at your own situation and what kind of riding you will do, if $$$ is no issue go big or go home - lol.   I love the 500, so far it has not let me down and has plenty of power and speed for me and the wife. 

So many factors involved. $, riding style, riding locations, payload ( including passengers), functionality etc etc.
the one thing I've considered when I were shopping. I looked at the Viking and Wolverine before buying my Z800. Yamaha 700cc single cylinder vs CFM 800cc twin cylinder. The thought that kept crossing my mind is...... although I don't need a ton of speed and power which engine will be working harder to do the same task?
(IMO) a larger engine has less stress put on it than a smaller one doing the same tasks, hence giving it a longer life span (again, caring for them equally) .
Just the thought that made MY decision for me.

I've spent time in both, if budget is not a consideration then the 800 all the way. The 500 is impressive power wise, the 800 loafs along @ trail speed while the 500 is working. Noticeable difference in buzz & vibration, especially when you start closing it in with windows.

V Twin is easier on the ears, more pleasing than the single.

My single cent 

not a cfm owner...yet aleast...but go for the 800....done the mistake 3 times!!! started off with a 450 kingquad and i was like dang want something with a little more power....got a can am 500 in miami....i was like yes!! few months later...wanted somethhing with more power.... ended up getting 570 polaris in colorado thinking that was enough....now I want a 1000 to not make the mistake again ha ha.

once my 570 is paid off, trading that guy in for a 850 or 1000

I must be a different breed completely. I have an appreciation for the small motors. My riding style is hunting and crawling through rough terrain. My machine idles frequently when hunting, and I will frequently let it idle while I'm hooking up trees or my brother in laws arctic cat, etc.. LOL! The small engines do everything I like, but always do it cooler. I would like if my 600 would sustain speed better when cruising down the trail, but I very rarely trailride dirt roads. That's all we have here in Northern Maine.

I work my little 600 severely on my own 80 acre woodlot. It has been a very good machine.