I believe testosterone starts to level out after about the age of 2, it no doubt varies from dog to dog and breed to breed. Up to when it levels out it can spike at various times hence the teenage phase etc.
The implant may work out more expensive in the long run but it's not permanent and if it doesn't help or makes things worse it will wear off and things will revert to normal. Castration on the other hand is permanent and if it has a detrimental effect on his behaviour there is no turning back.

The only problem I can see with the implant is once the dog becomes fear aggressive (which can happen) will the resulting behaviours be permanent or fade as the implant is got rid of ?

Personally, if your dog displays any temperament issues, I would not have him castrated.

The implant does come in two's that is correct. I had to pay for two when I only had one dog done, but of course the second one was free. The implant is 100& reversible. An operation can never be rectified.

Why do you want a healthy dog operated on?

Having just read your other threads, your female is already spayed so why are you bothered about getting Sampson done. He isn't being a sex pest so why do it?

I don't want him done really Borderdawn, just want to get away from some of his behaviors, but I guess training them away would be better and if the evening out of testosterone isn't too far away then that is cope able, Aw I feel bad for thinking about it now you put it like that
The vets meant by paying 2x was 1x for the implant and 1x for the chop, but of course it may put me off it altogether.
I think I will spend the money on a behaviorist instead (when i've saved it).
Sasha has been done so no worries of pregnancies

Trouble, the worst problem I have is his non tolerance of other entire males, and this nipping thing, but that won't be altered by castration anyway, So I will get a behaviorist on board asap x

You shouldnt feel bad at all. If you have a dog aggressive dog removing his testicles wont change that. Castration is not a "cure all," it very rarely helps in behaviour issues because testosterone is so important for a dogs confidence. Vets push castrating because they are taught to, we are among the only countries in the world that advocate pre pubescent neutering, despite the proven problems it causes. In country's like Norway for example, its against the law to have a dog or bitch neutered except for medical reasons. Its considered unnecessary mutilation. The Vets and owners face prosecution if its done without good medical reason.

I would highly recommend you getting a behaviourist I can see a difference in just a week make sure the person is a APBC. Can you get a referral from your vet for one. My husband was very anti in getting one so your not alone on that one. Have you got pet insurance some will cover this if vet has referred you. I am going to try on my insurance.

Thanks Borderdawn and Lablover, The vets refer to 1 here but she is solidly booked, there is a couple a bit further out and from speaking to them they sound great, there are no apbc in my area though when i looked online
I gave up on the insurance a few months ago but they are only just more than the down payment anyway, think the most expensive one I spoke to was £150.

It is very interesting to hear about other countries only castrating for health reasons, It has been practically pushed on me since he had his first check up at 9 weeks old, They make me feel that i'm doing wrong by him, not getting him done
So it is good to see that it is not essential, he is not so bad really