I've got the Timney and, to be honest, I'm very impressed. The bigger downside of it is that it's not adjustable like the Kidd. But the Kidd is also costing nearly double, and it is much harder to get ahold of one.
I'm more than happy with my Timney though. I may pull it apart and polish it just for kicks, but as it comes it really is a good trigger. Don't have any complaints with it at all.
I can't imagine that any trigger parts upgrade, be it Kidd power custom, home made sear mod, etc, would be as good as either trigger group (Timney or Kidd).
If you want something now and don't want to pay nearly 400 dollars, the Timney is a great option. Another option still is the parts upgrade, but just don't expect it to be as perfect as your buddy's trigger group. It is cheaper though ... there's a company out of the Vancouver area (not a sponsor on here, but they are great people, Berry is a super nice and knowledgeable guy) and they sell green mountain barrels at a decent price as well as power custom update parts. The cost of the trigger parts for a full upgrade was really very reasonable (don't remember the exact price, I ended up getting my barrel and ti charging handle from this guy, and got the Timney instead of power custom parts, Timney came from Jerry at mystic precision out of Summerland bc)...so it's an option but imo the trigger groups are the way to go, I think anyone who really can't stand the factory trigger will be annoyed with the parts upgrade after some time with it.