Hmm... I suppose at some point GalBoomer could have typed up an autobiography and sent it to CapSharon, who then managed to successfully impersonate GalBoomer based on the facts she knew and their identical personalities, even though she didn't actually gain the memories. [/quote]

It all really comes down to how much the memories of the Cylons are or are not just elaborate data files.

Obviously Cylon agents should (consciously or not) make regular reports back to home base if it's possible to do so. I prefer the idea that those regular reports are not equivalent to Full-On Uploads - digests of text data, important video clips, and perhaps a rare few model-specific emotional-impressions. Only a "resurrecting" Cylon would get the full-bore total-memory experience.

The possible bits of memory and personality for any given individual Cylon include:

1) Universal basic Cylon knowledge (suppressible in agents).
2) Basic template personality parameters, specific for each of the 12 models.
3) (Optional) Excerpts from an expanding "basic memory database" for that model.
4) (Optional) Total Life-Experience Download from a just-deceased Cylon of the same model, including whatever universal and model-specific Basic Memories it had started out with.
5) (Optional) Specifically-crafted cover-identity knowledge and memories, flagged as either "genuinely believed" or "known to be false" depending on the new unit's mission.
6) (Optional) Excerpts from higher-security levels of universal yet restricted knowledge/memories, based on a unit's Need to Know.
7) (Optional) Post-activation uploads of data from the Cylon network, possibly including updates from that model's expanding "basic memory database", limited by personal interest, model-specific compatabilities, and/or access restrictions.
8) Personal, individual memories and personality adjustments acquired in the time since activation (PegaSix is not the same personality as ChipSix, natch).

For a fresh-minted Cylon who's expected to stay on the Cylon side, they'd get 1, 2, and 3. A normal individual would regularly connect to the network to get 7, and would acquire 8 naturally.

For a resurrecting Cylon, they'd pretty much just get 4, which would include (possibly outdated) versions of 1, 2, and 3. Connections to the network via 7 would catch the individual up on anything "universally important" to its model that it might have missed due to separation. (The only real difference between a freshly minted Cylon, a long-lived Cylon, and a frequently-resurrected-yet-updated Cylon is the specific accumulated life-experience any given one happens to have.)

Cylon sleepers would get (suppressed) universal data from 1 and 3, the basic personality template of 2, and the elaborate "false life" of 5. Any mission specific implanted or uploaded knowledge from 6 or 7 would remain suppressed from the conscious mind.

Hypothetical "Cylon leaders/priests/prophets" would get 1, 2, 3, and a heavy dose of the supersecret goodness in 6, including specifics about "the Plan" and whether or not the God Cylons talk about is, secretly, less than an omnipotent abstract spiritual Creator and more of a hidden Wizard-of-Oz-esque human or toaster or manputer or femputer.

All Cylons in range of the (standard, non-Upload-level) communications for the Cylon Network would regularly download the "updates" of number 7. Data coming from other models or Raiders would be "book learning" intellectual knowledge. Data coming from the same model could be merely intellectual knowledge or possibly "something to remember". If it is "something to remember", it's also added to that model's Basic Memory Database for future freshly-minted models.

I'm guessing that CapriSharon was either freshly-minted or freshly-updated when we first see her. She knows, in at least intellectual-knowledge digest form, everything general that happened to GalactiSharon up to GalactiSharon's last secret report, as does every other Cylon everywhere that needs to know. CapriSharon might have knowledge of GalactiSharon's "super secret special" missions and codes, if CapriSharon is flagged as Need to Know. Likewise any other Cylon anywhere who is so flagged. Anything that got downloaded from GalactiSharon in full-memory mode would be something that CapriSharon can "remember", but that any other non-Sharon Cylon with a need to know would have access to only as intellectual data.

When GalactiSharon got shot by Cally, it would be my expectation that, somewhere, an inactive, freshly-minted Sharon model got the Total-Experience Upload, and then proceeded to post a digest update to the Cylon network. All Cylons with a need to know would have the details of her experiences on their next connection, while other model-Sharons would also get full-memory "remembrance" of anything deemed worthy of being added to the Sharon-model Basic Memory Database (not much, probably).

So we can explain how CapriSharon was intellectually aware of what Leoban said to Starbuck, if we assume that his Total Upload got relayed into a waiting, freshly-minted body, and then reported to the Network.

The fact that CapriSharon seemed to be unaware of the specifics of how GalactiSharon died, until she was told on Kobol, means that she was not able to download that information, either because she was frozen out of the network or because it was considered information she didn't need to know, and thus not available to her when she did hook up.