First, I would check your TV owner's manual. It will tell you at what weight the WD hitch is required. Having said that, I would recommend the WD for any long trips, especially. It will tow better and will be safer.
Our first TT was a popup that we were towing behind the minivan (yeah, I know...crazy). We had a WD hitch as it was needed with that TV.
We pretty quickly thereafter upgraded to the Exped as a TV. The trailer was WAAAAY under the weight that requires WD (6200lbs on the Exedition), and since the WD hitch was not adjusted right for the Exped, and I didn't have the right tools to adjust (and it was time to leave when I figured all this out) I just got a plain straight hitch/ball to use.
So I towed the popup with just a regular hitch for a few short trips and for short runs in good weather it was fine. Then we took it from NC to Baton Rouge, LA and back. That light trailer bounced all over the road behind my Expedition at speeds above 55, especially when passing Semis and if it got windy. While it was techincally 'safe' it was nerve wracking to say the least. It felt like we were getting sucked into every semi we passed.
If we hadn't traded in the popup I was going to take in the WD hitch to my dealer to adjust for me to use with the Expedition - there was no way I was going to tow that popup without that sway bar again for any distance.
Of course with the larger trailer we are over the 6200lb point where WD is required, so we use it all the time now.
That's my experience in towing with and w/out WD...
2012 Flagstaff V-lite 30 WTBS
2011 Ford Expedition
4 kids and a hubby & never enough time to camp!
2011: 17 nights 2012: 26 nights 2013: 46 2014: 20 2015: 16