[CentOS] Are SSD disks worth the cost for server usage?

Hi,

we want to upgrade our infrastructure and are considering renting two
different types of server by a provider:

- A: one is with 80 GB SSD (and 12 GB memory)
http://www.ovh.co.uk/products/eg_ssd.xml
- B: the other with 750 GB SATA2 (and 8 GB memory).
http://www.ovh.co.uk/products/eg_best_of.xml

The target infrastructure will host:
- a few public web sites (PHP / MySQL)
- a development infrastructure (subversion, bugzilla, automated builds)

This will use KVM virtualization with Cent OS 5.4 hosts and guests.

On the long run we will probably rent quite a few of type B depending
on our needs of space and computing power.

My question is whether it is worth using one of type A (with SSD
drives) in order to host the critical data such as the web sites and
the subversion repository (critical in the sense that these services
should be fast, always available, and the related data as safe as
possible).

This critical server will be more read oriented than write.
We will probably use a hardware RAID 1 with battery backed unit on it.

My understanding is that SSD are much much faster.
Is it really true in the real world?

Are SSD drives also safer?
(that is, less likely to crash under load)
Or to the contrary?

I have read/heard conflicting opinions so far and I'll be happy to
hear opinions/experiences on SSD drives in a server settings from
people on the list.
More general comments about our plans are always welcome of course!

Cheers,

Mathieu

PS: we will actually rent them in France, but I put links to the
equivalent in Britain in order to have the description in English.
For reference and for the French-speaking people, here are the actual
servers we consider:
http://www.ovh.com/fr/produits/eg_ssd.xml
http://www.ovh.com/fr/produits/eg_best_of.xml
(they are exactly the same)