I have been testing 4.0 Beta on both desktop (Intel Q6600 w/XP SP3) and netbook (Atom N260 w/XP SP3) for at least four months, and no trouble was identified so far. Here’s my impression of Beta 4.0:
When considering the cold boot time, eBoostr will be the most effective for the system consists of Windows XP, Slow HDD, and fast USB drive on USB 2.0. A person who has such PC will clearly realize this tool is effective.
Once OS is fully loaded, then SD card would become a better cache device than USB drive. Using system RAM for cache may be a bit risky (therefore a warning appears when I try to make the function available, I guess…). For those who have faster PC, I recommend to use Class 6 (or 10) HCSD as cache device, and accelerate applications by adding in the priority list. In this case, we cannot expect drastic change in the boot time because the PC does not recognize SD card until OS loads the card reader driver, unlike USB drive, which is recognized at BIOS level.
I wonder if we can separately manage files when building cache, like; OS system files required at boot stage to USB, and other OS files and application files to SD or RAM. I think this would maximize the benefit of this tool.