Have been doing some experimenting for the last day or two, and came up with some findings for Photo Caller ID and/or custom ringtone programs. I think it would make a good FAQ too... Hahaha.

Ringo Mobile
Broken software. It can't load ringtones from SD Card, some error message that ringtone from storage card is not supported by my phone... WTF. It does not have Photo Caller ID features too. And worst of all, you must manually add the contact into the custom ringtone list (i.e. if you have 100 contacts, you have to manually create 100 new custom ringtone entries in the program).

Inesoft Address Book
As reported in one of my previous threads, I'll just give you the jist of the information.
- When the ringtone is loaded from ROM, both Caller ID screen and ringtone initialises within 3 seconds (roughtly 2 "rings" at the caller end).
- When the ringtone is loaded from SD Card, ringtone initialises by the 5th second (roughly 3-4 "rings" at the caller end). However, Caller ID screen only appears after the 11th second. (Now, this is a very peculiar problem. If the ringtone can load from the SD Card by the 5th second, I don't understand why is there another 5 sec delay for the Photo Caller ID to load, which is running off the ROM exclusively. I've emailed Inesoft this morning, hopefully they will give me an answer.)
- I tried shutting down the Caller ID feature, but that makes things worse. When the ringtone is loaded from SD Card, both ringtone and the "Incoming Call" popup only initialise after the 11th second!
- FEATURE LIMITATION: Unlike Photo Contacts Pro, Inesoft Address Book doesn't have call blocking feature. The Photo Caller ID display page is also not customisable, but for me the default setting is fine.

Photo Contacts Pro
This is one serious broken software. Read on...
- When the ringtone is loaded from ROM, both Caller ID screen and ringtone initialises within 3 seconds (roughtly 2 "rings" at the caller end).
- When the ringtone is loaded from SD Card, both ringtone and Caller ID screen intialise after the 13th second.
- BUG: When you change the custom ringtone for a contact, Photo Contacts Pro will still continue to use the old ringtone until you do a soft reset.
- IRRITATION: When I close Photo Contacts Pro, the program really closes itself, unlike Inesoft Address Book where the Caller ID monitoring program will still run in the background.

Why is there a tremendous lag when running ringtones of SD Card?
As stated in the Photo Contacts Pro documentation (and a lot of forum sources), whenever we receive an incoming call, the phone is powered on. However, there is a "Wake Up Time" for the SD Card, which is responsible for the lag. Of course, I am assuming your phone is powered down when the incoming call comes in.

Will changing to a super-duper 100X 4GB SD Card help?
In my opinion, I don't think it will make a significant difference, because my hypothesis (and from the various comments from forums) indicate that the bottleneck is in the "Wake Up Time" for the SD Card (which may be device specific or OS/Registry specific). However, I've not tested my hypothesis on this. I have a feeling hacking the registry for the "Wake Up Time" may have some bad side effects too...

Conclusion aka Bottomline
For me and any other person, I think the max we can afford is a 5sec delay (considering we have a 30sec window).
- If you run your ringtones off the ROM/RAM then either program is fine.
- If you MUST run your ringtones off the SD Card (like me), then Inesoft Address Book is your best bet. Why? Cause you start hearing your incoming call by the 5th sec instead of the 13th sec. Also, if you do have custom ringtones, you will probably know who is calling you, and by the time you take your PPC out from your pocket/bag, the Caller ID screen will probably have loaded by then.

Of course, these are my findings. If anyone has contradictory experience, please point out ok?

Moderator's Note:

Thread moved to Tips and Tricks

Adding to this is that no matter which high speed Storage Card you use, you will still experience the delay in ringing due to the reason given above.