Bio filters? Eheim Wet/Dry

[rvm]

I'm looking at changing the Fluval 404 on my tank to an Eheim Wet/Dry 2229 Filter. I will use the Rena XP3 I have as mechanical filtration only (and chemical when needed), and have the eheim as Bio filtration only (as it is intended!).
Does anyone have any experience of these filters as I have heard mixed opinions. Most reviews I have read have said they are great, but the guy in my LFS said don't bother and get the pro II instead (probably because they don't stock the Wet/Dry ones?) and a couple of other reviews have said that Eheim were being too clever for their own good with these filters!!
Also would it be best to set it up so that the intake of the Eheim is as close to the outlet of the Rena as possible so as to put the cleanest possible water through the bio media as possible?
I know this should really be in the Hardware section, but I'm not really getting any answers to my post in there and I'd like to know ASAP as I have the possibility of getting one from a guy I know for less than £100 brand new!!

 

[CFC]

The wet/dry filters are victims of their own success, they are so good that they convert ammonia and nitrite so fast that it causes horrendous nitrate levels and lowers oxygen levels (increased bacteria uses more oxygen). It is this reason that most marine fish keepers have now moved away from wet/drys when they were once considered top of the line. I agree with your lfs guy, go with the pro2 model or if you just want a very basic but highly effiecient bio filter go for one of the classic range. I use eheim classics on all my larger tanks and have found them to be great, they lack the modern features like self priming and a light to tell you when the filter needs cleaning but to be honest i have no need for fancy gizmo's and find the price of the classics much more wallet friendly.