Self-service back massage
The problem with other percussive massagers is that it's hard to use on your back without someone to help. Not everyone has the luxury of having someone do your back for you.
If that's the case for you, rather than get the Theragun or Hypervolt, you're probably better off with the ELEEELS X1T. It has an adjustable handle that makes reaching your back so much easier. However, it's still better if someone is doing it for you though if they know what they're doing.
The adjustable handle also makes it easy for you to use on someone else when you set it at a comfortable angle.
The X1T has two modes: sports mode and comfort mode. According to ELEEELS, Sports mode is for keeping your muscles awake and in a state of vitality. Comfort mode relaxes the muscles to aid in rest and sleep.
In Sports mode the gun operates at a high frequency with 3 speed settings (level 1: 1800rpm, level 2: 2400rpm, level 3: 3200rpm) and Comfort mode at lower frequency also with 3 speed settings (level 1: 900rpm, level 2: 1200rpm, level 3: 1500rpm.
The Li-on battery on the X1T lasts for 3 - 15 hours depending on the speed used. ELEEELS claims the device is quiet during operation.
ELEEELS X1T vs Hypervolt Plus vs Theragun
In some ways, the ELEEELS X1T is quite similar to Hypervolt. They're both quiet, they both seem to use the same battery, both have a brushless motor, and the highest frequency for both is 3,200 rpm.
The difference is that the X1T has 6 speed settings while the Hypervolt Plus only has 3. Also, the X1T has an adjustable handle while the Hypervolt does not. The X1T retails for $420 and the Hypervolt retails for $449.
In comparison, Theragun's top-of-the-line model excluding the ridiculously expensive 24K Gold Edition G3Pro ($1,200), the normal G3Pro is $599.
In terms of performance, the Theragun can go deeper in to the muscles than the Hypervolt due to the longer stroke length. Both Hypervolt and the ELEEELS do not mention their stroke length in the literature but I bet it's about the same.
If you have thick muscles, both Hypervolt Plus and ELEEELS might not be sufficient. For the heavily muscled, you need a Theragun.
The problem with Theragun is that it's extremely noisey compared to both ELEEELS and Hypervolt.
For most people, the ELEEELS X1T is the most useful compared to Theragun and Hypervolt thanks to the adjustable handle that's not only comfortable to hold but also allows you to reach your back on your own. It's also quiet. If these matter to you, you should really consider the X1T.