Metal Mouth Message Board

So I am about to invest in a Waterpik
didnt know there were so many different one to choose from but think i have narrowed it down to
Waterpik Nanno
Waterpik Ultra

I was going to go for the portable one but on the web there seems to be a few bad reveiws

I am not sure I need 500 different types of attachments ?

any advise would be good
I live in the UK so has to be UK model

thanks

I wouldn't get a portable one for every day (the reviews are right!) but if you travel very much it is well worth having one.