After careful consideration I have decided to buy either the Vestax VCI-400 or the Pioneer DDJ-SX2 (I will be using Serato DJ).

Despite the VCI-400's age it still is a very interesting candidate, mainly because of the big hardware filters, the compact size and the ability to play Decks C-D whilst remaining on decks A-B.
However, I do find the 'performance pads' quite hard and oddly placed (I'm currently on a Novation Twitch and so I'm used to having the pads before the jogs), especially when compared to the soft (and big) pads on the SX2. The lack of booth output is a big shame as well. Another concern is the fact the Vestax is in serious economic difficulty, although this isn't as important to me as the previous reason.

The SX2 is a spanking new controller with the Pioneer build quality and reliability. It does everything the Vestax does and more (aside from playing decks C-D from A-B, could be solved with some cheeky mapping) in a bigger, less cramped controller. However, this is also why I haven't bought it yet. It's huge, and being quite a DJ in London (i.e. no car) it could be a big weight, both physically and in terms of mobility.

The price difference doesn't bother me (around 250 euros) as long as I get a controller that isn't going to be obsolete in 2 years (basically as future proof as the VCI-400 was in 2011)

Out of these two, which one would you guys recommend?

Cheers