I think the longest I got out of a chanter reed was about 2 years.
My current reed seems about to give in (had it about a year but played the shite out of it)
Wonder who holds the record? 
20 years now but recently I decided a chanter made to the latest design would be a bit of a boost. The maker agreed and duely started work on the new one so in some six weeks or so I’ll have a new chanter. A bit like replacing the car before the petrol runs out but what can you do?.
Into my 3rd year with a Charles Roberts reed.
The longest I have had a reed last was approximately 1 year or so… I keep handling them carelessly, dropping them, smashing them…
Yesterday I was putting the windway back on, when I sneezed suddenly, resulting in the windway splitting the reed right down the middle of both blades to the binding… pity, it was a great reed.
But, I have loads of them, and currently the one I have in my chanter is a good one that will become really good once I have played it in for a couple of months… that is, if I don’t accidentally step on it or something similar. 
I am still playing my original Charles Roberts reed that I received with my pipes in 1998. It has performed flawlessly for almost 8 years now. I have tried a few others, but none compare.
In the beginning (4,5 years) I was handling them carelessly
My pipemaker (mr van Daal) told me to leave them alone
Now I am playing his chanterreed for 3 years
I wonder if I need a new reed after I get 3 more keys
My original reed I played for about 1.5 years, my new reed, .5 years.
5 years.
The spare is a bit like Michael Owen abroad…keeps asking for a free transfer so it can get playing!!
B
Nearly 2 years so far, and it shows no signs of giving out yet. I keep wondering how long it will end up lasting, and hoping it will be a long time, because I’m sure it will be a very long time before I’ll be able to make a decent replacement.
The one I have now I made 3 years ago. The one before that was 9 years on the go.
It’d be still going if it wasn’t cracked ina car crash. I broke a leg!
Tommy
Dunne made reed now 1.5 year with his chanter, ever no" biiig" problems , just something local humidity effects … after quite hard season here with cold temperature +
quite dry air , reed is now, with bridle adjustings going well, but abit "maintenance"with back D against moving with between two octaves ,
gurrrledeeeddd …, very sensitive with pressure.(Lower D and others just fine).. reed lips are really thinshaved.
Current Seth G concert D reed going for 4 months and it’s still getting better.
Playing a reed in my C Angus chanter that dates back to 2003.
The reed in my Herriott and Alan Northumbrian D chanter is dated 1992 and works very nicely.
Well…I’ve been playing my reed for about an hour…and LOVING IT! 
'Tis in my newly aquired Kirk Lynch narrow bore D chanter. I believe the reed is by Alan Burton.
Wow!!! Now I guess I’ve officially gone over to the narrow side of the dark side. 
Paul
P.S. My concert chanter reed is 8 years old…that’s how long I’ve had my Lynch concert set. I’ve newer reeds for it but I keep going back to the tried and true.
4 years on my first Kirk Lynch reed, until I took it to Swannanoa back in 2002 and it couldn’t handle the moisture of North Carolina and exploded. Second reed going on nearly 3 years now, built by David Coultrup here in SoCal.
Andreas Rogge B Plumwood chanter with first reed lasted from
Dec 2001 - April 2005 (4 year 4 months). The reed I am using now is by A Rogge at Cultra Tionol Sept 2005. I have also B reeds made by Alan Burton March 2005, Alan Ginsberg Sept 2005, my own reed Sept 2005.
Andreas Rogge D Plumwood chanter with first reed lasted from
Jan 2004 - May 2005 (1 year 4 months). I have new Rogge D reed made May 2005 and also reeds by Alan byrton and 2 by myself Sept 2005/Jan 2005.
Andreas Rogge C Snakewood chanter with first reed lasted from
Sept 1997 - May 2003 (6 years 8 months). Got new reed made by Rogge Oct 2004 and I didn’t make any reeds for theis chanter. The full set C snakewod was sold in April 2005 to Andy May Northumbrian smallpipes player with the C reed made in Oct 2004.
Cheers
Ferg
My first reed (Thompson) lasted from 1996 to 2001 but died very quickly after I emigrated to Canada. The next reed (Joe Kennedy) lasted from 2001 to 2005 but died very quickly after I messed with it once too often. Since April 2005 I use a reed that Nick Whitmer made. I alternate this with a reed JES made. I also had a nice reed that upiper1971 made but once again, I fear that my eager mind and clumsey fingers sent that one to an early grave.
tom kennedy made my reed in 1991. its been in the chanter since 1994. i’m very lucky.
The reed in my Fischer narrow bore concert pitch came with the chanter in 1995 and is still going great, as are all other reeds in the set though I have made replacements for all except chanter. Have not been able to make as good a reed as the original.
The reed in the Woof B chanter from 2001 is still going great as are all others.
The secret? If you’ve got a good reed dont mess with it.
The reed Im playing has started to get weak and feeble. and sounds as though it’s all blown out. it was a wonderful reed. 
I feel your pain man, I feel your pain. I think you need a good stiff drink…