adding a controller, when you dont need it, really just adds to heat, change in airflow, system resources, and more power consumption... yes, they may be just minor little changes but such things can change system stability.
i'd say, if it works, great, dont re-fix-it. but its your call on what you want to do. we'll still help ya either way.
on a side note, did you try the slip-stream? and, if you do decide to get another card, slip-streaming all your 'floppy' drivers onto a cd will save you time.
SYSTEM-1: 2x Viewsonic VX900-2 19"
| Tyan S2885ANRF (Rev.A, bios v2.07)
| 1x ATI Radeon X800 Pro 256MB | 2x AMD Opteron 248-HE Single-Core CPU | 8x 512mb PC3200 Corsair XMS Series ECC Reg. (CMX512RE-3200LL) | 2x Seagate LVD 36.7Gb U320 SCSI 10,000rpm RAID0 (ST336607LW) | 1x Seagate LVD 36.7Gb U320 SCSI 1