I've never used a UPS for anything including my studio and never had a problem, I also live on the outskirts of lightning alley near the GA-FL state line and have gone through many thunderstorms since I moved to this location in 1975, but Georgia Power is one of the best electric companies and I have all of my gear on their own breaker separate from ac, lights, microwave and coffee machine with isolated ground going to an 8 foot grounding rod sunk in the earth outside. The building lights and electricals are grounded to the water main via the water pipes in the building which isolates me from using the same ground.
The D2424 has two drive bays, I back up my multi-track studio and live remote recordings to 120 GB drives formatted in FDMS (Fostex Disk Management System) and final two track masters, clones of the PMCD's from my mastering service are stored on 80 GB's. My cost for the 120 GB's is 50 cents a gig to record or archive. If I want to edit in a DAW, I run real time all tracks or a combination of the ones that I want to work on, than transfer them back after editing, so I'm always mixing from the HD-R not a DAW program. The D series Fos HD-R's have had a feature that they implemented back in early 1996 that uses a sync tone to align tracks that are saved to outboard sources, such as SCSI, ADAT, AES or SPdif devices. In this regard I transfer any combinations of tracks to DAW's for editing and specific processing and back. For over 10 years, always sample for sample accurate and never had a track not line up perfectly using the sync tone save and load back. You can use whatever ports you support with that feature, ADAT and SPdif optical are stock, AES and Tdif optional, SCSI 2 is stock, so that you can transfer to DAW's via SCSI or with single drive bay units to external scsi drives.
You can format a drive for .wav in the D series HD-Rs, however that limits you to the file size limitations of .wav, there are no file size limitations with FDMS, it is rock solid dedicated to audio only linear recording format, so I could record one file to a 120 GB, although the recorder will disarm at 24 hours of straight recording time when the display turns over. The largest I typically get are about 20-25 gigs for a two hour show, though, running 44.1/24. Last concert I recorded was 13 to 18 tracks, 4 bands and used 55 gigs total. I sometimes turn the recorder on, let it run the whole time and than save the different shows to new song program slots back at the studio, using paste and move function, thus separating sets to their own programs next day after the event.
Transfer from the recording drive to the second drive is about 3.5MB per second, or a little less than 5 minutes per gig-a-byte. which is slower than saving a project in a DAW via .wav or aiff, but it's a set it and forget it thing transfering between drive bays and I find it's much more stable than saving via DAW programs and .wav/aiff. I use the jog/shuttle editing quite a bit for basic edits without leaving the HD-R. Transfer between drives using FDMS format archives all location points, song titles, track titles, slave/master relationship, frame rates etc. and also this non-audio data is transferred and stored on the audio track pre-roll just before the sync tone if I go to a DAW using the sync tone save method, so no midi or SMPTE is needed to transfer tracks between devices and keeping them sample for sample accurate on the timeline, while maintaining the non-audio data going to and back and I've eliminated any type of midi latency or problems associated with having to use SMPTE, or MMC and MTC for audio only non-AV apps when transferring between digital devices.