Hi,
I have the regular 3 but not the newer 3e. The original 3, such as the 2080 works fine and is quiet. Like all filters it only delivers half of it's rated throughput when filled with biomedia and attached to CO2 diffusers etc, but this is normal and is taken into account by the 10X rule.
What irritates me about the new 3e is the feature set which is introduced by the fact that it's a "smart" filter. This is marketed as if this filter were some sort of cruise missile. Take a look at the marketing hype below and see if there is anything even remotely useful for your tank, fish or for plants:
1 Output Control - maintains constant set output automatically, adjusting for filter media blocking
2 Boost Function - by simply pressing a button the filter switches to maximum turbo filtration
3 Flow Regulator - finger tip control of the flow rate.
4 Service Check - at the touch of a button the filter calculates the time remaining till the next cleaning interval. (whoop-ti-doo)
5 Pulse - electronically controlled alternating flow rate creating a wave like effect.
6 Self Test - automatic testing and removal of trapped air
Now, do we really need a "smart" filter? Have a look at the filter specifications which have a direct impact on the health of your tank and compare this 3e to the less sexy 3:
Parameter_________________3e (2076)________________3 (2080)
Pump Output:.......................1650 ltr.......................1700 ltr
Delivery Head:......................2.4m..........................2.8m
Filter Volume:.........................6,6l (6 + 0,6) Prefilter ...12 ltr + 1.5 (pre-filter)
Power Consumption:................10-35 w......................45 w
Dimensions:...........................474 x 264 x 264. ..........567 x 330 x 330
Price....................................£170..........................£190
Look at the fact that the 2080 has almost twice the filtration capacity at a stronger delivery head for only £20 more. Yes, it costs you more to fill it with biomedia, and yes the power consumption is 30% higher but you would expect that. This extra capacity is what removes ammonia. Unless the dimensions don't fit your cabinet, I can think of no reason whatsoever to choose the 3e over the 3. Instead of meeting the challenge of the FX5 (with it's superior flow rate) Eheim has chosen to wow us with high tech features like "wave pulse". It would have been better if they had just put a stronger pump in the head, wouldn't it? I note that the 2078 does have a higher throughput but not enough that you will see much of a difference, and it still has less capacity than the 2080.
The FX5 has all of these beat on throughput at about 2300 LPH, however there may be some reliability issues. I don't own a FX5 so I can't comment on the reliability or the ergonomics, but if you are looking at raw throughput you might want to consider it.
Cheers,