I played around with the quickfix today. Its better than before but its still ineffective compared to the regular medigun.
The only thing the quickfix has going for it is the faster healing but besides that the regular medigun has a much more useful and effective uber (in fact the regular medigun's uber is CRUCIAL to a game, the quickfix's uber isn't) and also the quickfix doesn't have full overheal which defeats the purpose of it being a better gun for giving team mates health.
I play a lot of medic so I could see the noticeable difference. Really the quickfix only needs a bit more of a buff now and then it will be a viable medigun.
What this buff could be I don't know. More health for the medic? Area of effect healing whilst ubering? Longer ubercharge time (I find that the quickfix uber ends just as you see your team beating back the enemy)? Invulnerability to just the medic during uber (but no capping)?