I have replaced the leather, lining and hardware on over 12 pieces. I personally think that it is worth it - Although, for some pieces, the cost of refurbishment is the price of a new Louis Vuitton bag, another style of course.
I enjoy having new leather, new handles most of all - Especially for a hand carry bag like the Speedy. I had the leather replaced on my sisters Speedy, I cannot recall what the exact total was, but it is in a previous post. Once the search feature is back, I will link you to the thread.
The biggest issue with having Louis Vuitton items repaired, is the time frame. It always varies and there is no time guarantee.
My most recent repair took 2 months, 1 month for them to give me the repair estimate and 1 month for them to repair it and send it back. On top of that wait, they sent the bag back without replacing the handles (it went in for a complete overhaul) - So they sent it back to the repair facility. It took another 2 1/2 weeks for it to be returned to me and this was a "Priority Rush" repair. This only occurred because the repair facility is undergoing changes.
The longest I have ever waited for a repair was 4 months and that was due to very poor communication between the boutique and the repair facility. I no longer shop at that boutique.
If you are in need of refurbishment, I would highly suggest going for it. However, if you have more than one boutique near you, get estimates from each of them. I have found that each location will differ on the in-house estimate. Also, if you are a VIP/VIC, the replacement time is faster. My fastest repair was 2 weeks and I am a VIP/VIC.
Good-luck!