Not the same at all mate. The assessments are okay. They will send you a practice booklet, and they are near enough exactly the same as in there!
Assessments were mainly simple maths, simple English skills, and some fault finding/number searching (hard to explain you will see what I mean!)
You also do a comms test, where they give you a passage of info, and you must relay the critical information (not too bad, I got 100% on it first time! So relatively easy), the interview was more technical than I expected it to be (asked questions such as what would you do if a conpot was 'fizzing'), but I don't think they are essential for external candidates.
They did ask me questions such as what routes/stock do they use though.