If electric cultivators can't provide the gardening power you need, look to a gas-powered cultivator.
With powerful engines, you can take on more daunting tasks.
Also, if you're tackling a big garden, or one far from electricity, there's no cord to tether you down and no battery to charge.
The only decision to make is whether you want a 2-cycle or a 4-cycle cultivator?
Some cultivators are capable of utilizing many attachments to turn them into more multi-purpose tools.
You're already going to be aerating and weeding your garden, so if you want to edge too, then get an attachment-adaptable cultivator.