No!!!!!!!
Find out what sort of modem you ISP uses. If your ISP uses uses a USR/3COM X2/V90 modem then you're best off getting a USR X2/V90 modem; if your ISP uses a Rockwell 56KFlex/V90 modem then you're best of getting a Rockwell 56KFlex/V90 modem.
This is because the underlying X2 or KFlex technology seems to come through the V90 standard. That's why 3Com/USR modems always seem to benchmark well in the US, as most US ISPs use X2/V90 modems. However here in Oz they have a very poor reputation & always benchmark on the low side whenever magazines run tests, as virtually all ISPs in Oz use Rockwell KFlex/V90 modems. Hence generic Rockwell modems always benchmark at the top on tests in Oz.
If you do go for the Rockwell, I'd recommend a ACF ISA jumper modem (much better than HCF 'host controller' PCI winmodems). Since I replaced my Lucent PCI modem with a Rockwell ACF ISA Jumper modem, my modem connections went from a maximum of 47kbps to a minimum of 52kbps.
When you get your modem, check its PCB for its FCC ID number, then you can log onto the FCC website & enter the number in to find the actuall manufacturer & model number of your modem (many generic Rockwell modems are not actually sold under the same brand name or model number that they are made as). Then you can logon to the manufacturer's website & find out the correct 'Init String' for the modem, as optimised init strings will often help your modem perform better than general 'off the rack' Init Strings.