mazda 6 is quite good. looks are alright but not too great in my opinion.
i was actually considering it as my new car too, but changed my mind as time went on. nothing special.
2.3 sport mazda 3 is nice (looks better then 6 imo) but only if you are a relatively small person. i am way too big for it, so it should be a consideration. but is size is no problem - mazda 3 2.3 liter is sweet. i approve.
golf GTI on other hand is FANTASTIC. they new redesign for this year (not just visual - engine, handling, etc are way more important changes)
had a LOT of improvment gone to it.
so of you dont might a bit of reliability issues (as brand new car most will be covered by warranty anyway)
ps. mazda (even though its japanese) has its share of reliabily problem too. own brand new car had over $2000 worth of replacements under warranty within first year. so i am almost positive your problem experience will be partly based on luck, esp with brand new car.
so again, get the new gold gti - it is actually worth the GTI label again (just like the first one), unlike the models of past years.
http://www.channel4.com/4car/road-tests/V/...golfgti05-.htmltrust me, people who are complaining are basing their opinions on the previos models, not the new one. new GTI is quite special car. trust me, it is the one i would not mind be seeing. and i mostly like prestige bigger cars.
just test drive it

180 hp, 4-cylinder Turbo engine is the one used in audi a4, for last few years, and they were quite reliable.