If you are light weight you definitely want to try it. Wakestyle stable kite turns extremely precise. Light to medium bar pressure.
I was overseas early this year and saw a couple of guys throwing down some sick moves using Hi-Fi's (one in Boracay and one in Daet). I have no experience on this kite and I don't really like 5-liners but from what I saw these guys do with those kites... WOW! Having said that, there were a bunch of other guys also throwing down some sick moves using Switchblades, Flexifoils, Vegas, Nemesis, etc.
The most incredible sight I witnessed was this Romanian dude in Boracay who had 2 buggered legs. Due to a car accident, he could hardly walk, both his knees were locked at around 60 degrees, and he tiptoed to get around... but when he was hooked into a kite (the latest RRD Type-) he was doing back and front rolls, kiteloops, etc. 
dude, from what I saw those guys doing, kiteloops were a piece of p*ss for the hi-fi. 
If your only 50kgs I would look at either the 9m or 7m. They are super quick and loop easily. Worth giving one a demo!
to date hifis are still my favourite kites of all time.
ive changed brands a few times and will probably do it again next year because of the $$$ but im nothing but stoked on my 9m 2010 hifi.
its got quite versatile tuning so you can make it fly fast and loop hard or truck for bindings or set in the middle for a mint all rounder etc bla bla pimp pimp.
hifis have always been sweet for kiteloops, the first ones i had (original hifi) had some gnarly pull behind the loops, the 2010s refined and smoothed the pull out a bit but it still packs the same acceleration.
but all the same you should really go get a demo on one, asking on the forum you will just get personal opinions and everyone likes different things in kites.
i like them because they are powerful and you can go into tricks real fast to get lots of slack after pop, they make learning tricks easy and they depower enough so you dont get rolled every time you stack it ( i ride boots)
So if your looking for a good condition 2nd hand one im ya man as I am looking to upgrade 
charl in your posts are you talking about the hifi comp? or hifi? (when you say favourite kite of all time)
08 didnt have a hifi comp and 2010 didnt have a normal hifi
i owned both so i just generalise under the two names, never owned the 2009 models.
the 2010 hifi comp was pretty much a combination of the two 09s anyway from what i understood.
but both the 08 and 2010 i owned were nothing but a joy to own so i hpe 2011 come out with something good too
edit:
to be more specific what i think makes the 2010 hifi comp so good is its ability to change its charactaristics simply by moving the front lines around, put htem on the furthest forward and it flies forward super quick gives good slack n great loops, move it back and its grunty park and ride and mint for unhooked, i generally ran the middle settings as its a good combination and gives the best slack after pop.
the thing i miss about the 08 hifi is how raw it was, those kites threw you pretty agressively in loops when you did them right, the 2010s are smooth and refined so you dont notice that ball snappin yank you got from the 08s, that is what i missed.
