I've been using oral B electric toothbrushes for decades and this is the best one yet! I last had the 3000 and by comparison this (4000) has more power, the only downside to the additional power is the thickness of the handle, which is a little awkward to get used to at first. It has a three bar indicator on the front of the handle so you know where you are in the charging cycle, a very useful feature as you can then recharge before it starts to lose ‘juice’!
The deep clean mode is fab, it really does feel like I've just stepped out from the dentist and teamed with the floss action brush head I feel confident I'm achieving a really good clean. It also has daily clean, sensitive and polishing modes (as per the 3000). There is a separate button for scrolling through modes in addition to the on/off button. The icon for the particular mode lights up when in use so it's easy to check you haven't accidentally selected the wrong option.
The toothbrush beeps every 30 seconds, reminding you to move onto to the next quadrant of your teeth, usefully it counts where you are in the cleaning cycle by beeping once, twice, thrice and finally four times when the 2 minutes are up.
Best of all, from my point of view it automatically changes the cleaning mode to sensitive if you accidentally apply too much pressure when in use to protect the gums from over brushing.