Ok, here goes... [takes deep breath]....
I'm in the process of trying two Loree oboes, both about 20 to 25 year vintage.
Now, there is method in what may seem total madness. Over the last year I've found the Howarth XL suited my playing less and less. Maybe it's the thick wall of them that's no longer right, but whatever it is, it just isn't 'me'. The tone has become too heavy sounding, regardless of what reed I use.
Fortunately, I've been able to seek a couple of objective views from friends who are not musical, but appreciate music. We did totally blind tests so that they could see which instrument I was playing at any particular time, but both independently said my playing sounded far more 'alive' on a Loree than the Howarth. Additionally, the Loree is physically lighter in weight, so this may be having an effect on how I handle the instrument and therefore play. With this in mind, it would be interesting to know how I now sound on a standard S5, rather than an XL. Previously I'd found the standard S5 too brash.
Over time, all of us have a tone and style that develops, evolves and evolves again. I know that Andante_in_c had the same experience with her Powell flute, whereby it no longer suited her playing style.
The one instrument I still regret having to sell though, was my S20. It might only have been a thumbplate system and ranked as an intermediate oboe, but they are more than capable of Grade 8+ playing and the tone is rich but light. Maybe I should go back to an S20....
One huge dilemma on my hands now, that's for sure.
EDIT: I have kept the two old Howarth (1950s) S5 oboes that belonged to Terence MacDonagh. Apart from significant historical provenance, they have a tone that's extremely light. The down side though, due to their age and the amount of use Terry gave them, they are not really suitable for continuous daily practice