coffee script vs es6

Sensors.jsx

import React from 'react';
import _ from 'underscore';

class Sensor extends React.Component {

  cssClass() {
    if (this.props.toggled) {
      return 'on';
    }
    else {
      return 'off';
    }
  }
  render() {
    return <span className={this.cssClass() + " glyphicon " + this.props.icon} title={this.props.name}>Sensors</span>;
  }
}

export default class Sensors extends React.Component {
  render() {
    return (
      <span className='sensors'>
        {_.map(this.props.sensors, (sensor, index) =>
          <Sensor key={index}  name={sensor[0]} toggled={sensor[1]} icon={this.props.icon}></Sensor>
        )}
      </span>
    )
  }
}

sensors_component.coffee

{span} = React.DOM

SensorComponent = React.createClass
  displayName: 'Sensor'
  cssClass: ->
    if @props.toggled
      'on'
    else
      'off'
  render: ->
    span className: "#{@cssClass()} glyphicon #{@props.icon}", title: @props.name, ''
@sensorComponent = React.createFactory(SensorComponent)

SensorsComponent = React.createClass
  displayName: 'Sensors'
  render: ->
    span key: 'sensors', className: 'sensors',
      for sensor, i in @props.sensors
        sensorComponent
          key: "sensor#{i}"
          name: sensor[0]
          toggled: sensor[1]
          icon: @props.icon
@sensorsComponent = React.createFactory(SensorsComponent)