I upgraded my Winegard with a Jack OA-8000 last summer. I was having trouble with the Winegard - it would work sometimes, and not sometimes. I first tried the "wingman", but that didn't help, so I went to the Jack OA-8000.
The Jack OA-8000 is indeed about 10% better in reception.
I think though that the Winegard antenna might have suffered from a nearby lighting hit or something as I noticed it had been worked on by a dealer or the previous owner (because I saw evidence of a shoddy repair). Well, I am sure it was a dealer as the previous owner was a Doctor, and I don't see a Doctor having the time or inclination to climb up on the roof for an antenna repair.
Make sure though that you buy the OA-8000 and not one of the other models. The OA-8000 is designed to use the Winegard roof mount so you don't have to replace the roof stuff.
Simply remove the coax connection and two pivot pins holding the Winegard antenna, and put the Jack in it's place, reconnect the two pins and coax.
The biggest risk is losing one of the E-Clips.
Both antennas use 12V power up the coax as they both have a 12V amplifier in the antenna. The Jack OA-8000 also works with my Sensar Pro. However, one model of the Winegard Sensar antenna does not have an amp in it (no need for 12V power), so if you are replacing one of those antennas, the Jack OA-8000 does include a power supply.
My Winegard antenna had an amplifier and power supply though, and it was 100% compatible with the Jack.
Here is the Wingman I tried first. If you use one, make sure there is enough "real estate" on your roof to accommodate the addition when the antenna is stowed. The Wingman has no electrical connection, there are just a few "parasitic" elements cut to the higher digital frequencies.
The Wingman made absolutely no difference in my situation (however, this may not be quite a fair assessment as I think my Sensar was not working properly in the first place).
Jack OA-8000 on the Winegard Mast.
Here is the Jack OA-8000 and adapter plate for the Winegard Mast.
And you don't want to lose the E-Clips. This hardware comes off the Winegard antenna (pivot pins and E-Clips) and you re-use it when installing the Jack.
They give you two extra E-clips in the box, and with the two you take off the old system, hopefully you will have enough to finish. Keep the old ones for spares.
The only other thing I had to do was install a 90Deg coax adapter on the Jack antenna as otherwise the coax would be slightly in the way of folding the antenna down.
You get a few extra pieces of hardware and brackets with the OA-8000 so that you could mount it to a mast or on your house. But I didn't need any of that stuff so I pitched it.