In my experience, the only reason to go to an aftermarket T3 trigger is personal preference for a two stage pull, as I have with all my Tikkas. The factory trigger can be turned down to 12 to 14 oz without much trouble, which is quite light for anyone asking about the topic.
The Bixn Andy trigger from Germany looks nice, and being able to dial it down to 2 oz may well be nice, but personally I find a single stage hair trigger tough to work with. I used to have a Jewel trigger on the Finnfire that was set around 2 oz, and that was not what I appreciated. The two stage on my Valmet Standard has an initial pull of about 3oz and a break of about 3 as well, and I find that is a very nice combination- very very controllable. Last check at Roedale shows that the trigger is just under 400 Eur!
I have a TRG trigger on my Finnfire, which is quite nice, and found that it also fits the T3 action, as well as the 595 that I got it on. The drawback is that the TRG blade is built for a 'winter' fingerguard, and will not fit inside any of the Tikka fingerguards whatsoever, and must be swapped out for a slightly shorter trigger blade. The safety on the TRG and Tikka/ Sako triggers are interchangable. The trigger mechanism itself is quite nice- the break is a bit heavy, but with no creep whatsoever.
I put a CG Universal trigger on my T3 sporter, and I'm quite pleased with the feel of it. That was a lucky grab though, as CG hasn't produced that trigger for the T3 save for a quick trial production run. I think Peter at Hirsch Precision still has Cg's for the Tikka x5/x95 series guns, but the bolt stops on those triggers are a couple thou short of what they need to be to engage the T3 bolt. I wish it was different, as then I could shuffle the Barnard trigger I have on a 595 around to others, but sadly such is not the case. The CG is nice, break is at 500g and it is a good two stage design, but occasionally with concentration I can detect a hint of creep before the break. I can probably adjust that creep out if I dug into it, but I still enjoy the trigger very much due to the two stage design, and that the final break is lower than the TRG trigger, when set to its lowest setting.
The Barnard trigger is also a very nice trigger for the x5/x95 series. It's a little coarser in design... at the end of the first stage there's a metal on metal click as the contact points engage for the sear, but it's easily adjustable overall. The blade design is a bit ugly as well- a simple trigger bar in the same style that the TRG and CG triggers have would be nice on the Barnard, as then trigger options would at least be available.
I haven't seen or tried the Timney options, but I just can't see one of those manufacturers improving on the factory trigger enough to warrant the cost.
