Hyper Bicycles E-Ride 29" 36V Electric Mountain Bike (Grey) Expired

Let me touch on why this is not as good as a high quality e-mtb, not matter what you upgrade.
1) The pivots in the frame are small, AND they use cheap bushings. Bushings are actually good if done right (Ibis uses bushings in some of their suspension pivots), but owners of this bike report they wear out fast, and they are not lubricated.
2) The bike has pretty long chainstays. This means the bike will be more difficulty to turn around tight corners.
3) The frame only offers like 80mm of rear travel. Don't bother thinking you can just swap in a longer shock to get more travel, it doesn't work that way. Most good e-mtbs offer 140-170mm of rear travel. That's a huge difference.
4) The swingarm of this frame looks a bit anemic and weak. Look at the thickness of the tubing and all the welds near the dropouts. I've seen at least one person have the swingarm break in half at the chainstay.
5) The bike does not appear to be waterproofed well. Just look at the lack of grommet at the hole in the downtube above the motor. I don't think Hyper claims this bike is waterproof either.
6) The frame is not set up to run a dropper seatpost. Not a huge deal, because their are way around this, but it's something that should have been addressed when this bike was designed.

Things you kind of need to upgrade if you wish to use it a fair amount offroad:
1) Drivetrain upgrade. The cheap rear derailleur will cause a terrible amount of chain slap and will likely cause the chain to be thrown off. The freewheel has a pretty narrow range of gearing, and combined with the large chainring in the front, will result in difficulty climbing steep hills. Grip shifters kind of suck offroad, especially the cheap ones.
2) Rear wheel upgrade. First, the stock wheel is a huge weak point, as I've seen several reports of axles breaking and the freewheel breaking. Second, because it uses a freewheel, upgrading the drivetrain is very limited. A wheel with a freehub (vs freewheel) really opens the options up for great wide-range cassettes. Third, bolt-on axles suck, and a rear wheel with a quick-release is a huge convenience.
3) Brake upgrade. At the minimum, you probably want to swap out the brake pads for something with better bite, but honestly, hydraulic brakes (even the cheaper ones) are a huge upgrade, especially on a bike that weighs more than 50 pounds.
4) Fork upgrade. The stock fork would be fine for very occasional offroad use for a light weight rider, but serious riding will greatly benefit from a fork with an air spring (to adjust fork preload for rider weight), better damping, and thicker stanchions (less flex and deflection). Even a cheap $150-200 "take-off" fork would be a huge improvement.
5) Taller riders are probably going to need to swap out the bars with something with more rise, as the stack height of this bike is very low.
6) Dropper seatpost. Not a necessity, but it's nice to have. You don't really appreciate a dropper until you have used one. You can go externally routed and run the cable housing up the top tube and secure it with zipties and electrical tape, or use a dropper with the lever integrated into the post under the saddle, so no remote is needed. I'm not a fan of drilling holes in frames.

I got this bike on sale last year for $1298.00 and am very happy with it. $699.00 is a steal.
I've ridden and raced gas-powered bikes in the woods for over 40 years.And I rode all over Moab on MTB before there ever was suspension. I'm not on Team Red Bull but I can get through the woods pretty well, even at 57 yrs. old.
This motor is great and helps me up to the cell tower here (800' vert. climb) and I ride back down a nasty singletrack that is loaded with granite rocks. It's been handling it fine. Even better after I upgraded the fork. With the motor I can do multiple laps. With my analog bike I never felt like doing more than one. This motor is plenty strong and I don't think you'll find any stronger ones on other eMTBs. (look at the Newton Metres of torque, not the wattage)
The Vinka motor is very well sealed and is rated for non-pressurized water spray. The connections are no more vulnerable than any other e-bike. I have ridden through crank-deep creeks with no issues.
It's not going to compete with the specs. of a $3k bike but if you're ok with that you won't regret buying this bike. I'm tempted to grab another at this price for spares and/or a buddy bike for guests.
Hyper support has been great. Emails replied to within hours, in normal English, and knowledgeable folks on the phone. They usually have batteries in stock. Some other parts are also in stock. If not, they come on the slow boat but are very reasonably priced.
Check out Vegas Hyper Adventures on Youtube. He has a fleet of these bikes for his guided tours and does some good reviews. He bought his bikes just like us so he's not biased in his reviews.

If you have a lot more $ to spend then this is the next-level deal I would look at:

https://slickdeals.net/f/17330331-bulls-ebike-copperhead-evo-am-1-750-bosch-cx-2999?src=category_page

No, not full suspension. There's nothing else even close to this bike at that price. There are lots of options that are way worse. Keep in mind, it's VERY difficult to even find a decent non-motorized bike with full suspension for $1000. As critical as I may seem about this bike, I actually recommended it to a friend who was looking for something for his wife to use very occasionally offroad, and mostly on road and paved/gravel trails, because the Vinka motor system in this Hyper looks pretty good. He bought my BH E-motion Rebel Lynx (uses the Yamaha PW motor system) several years ago and loves it. I have a Haibike full suspension that uses the Yamaha PW-X system, which has also been a great bike. They are a huge step up in quality compared to this Hyper, especially in the frame design.