How important is SSD sequential write speed?

I'm looking at buying an SSD, and have noticed that sequential write speeds vary from pokey to blazing. I know that the random read/writes are what's really great about SSDs (except a few with J-Micron controllers), but am curious what the noticeably impact from the occasional slower-than-hard-drive sequential writes are. Those in the 35-45 MB/s range, for instance. Would it still be a drastic improvement to use such an SSD as a boot drive over a 2 TB WD Caviar Green even with those slow sequential writes, or would a move up to 90 MB/s really help?

The particular drives I'm looking at are, in order of speed:

Intel 320 Series SSDSA2CT040G3K5 40 GB (45 MB/s, $98)
Intel 320 Series SSDSA2CT040G3B5 40 GB (45 MB/s, $104)
Intel 320 Series SSDSA2CW080G3K5 80 GB (90 MB/s, $160)
Intel 311 Series Larsen Creek 20GB (105 MB/s, $115)

I reckon 40 GB is probably the sweet spot in capacity/price for me, without speed factored in. I like that the 20 GB one is SLC, as I still don't trust SSDs as much as HDDs, and it's the fastest write speed one. But I couldn't install as many programs on it as the 40 GB ones, so I might benefit less. I don't think it would be too small, but it might be smaller than is optimal.

Finally, can anyone tell me what the difference between the two 40 GB's is? I'm guessing one of them, probably the $6 more expensive one, is a newer revision? Spec-wise, though, they look identical to me. Is one of them the infamous 8 MB SSD? I saw less expensive OEM versions, too, but at this point I'd rather go with the longer warranty in SSDs.

 

Seems that SSDSA2CT040G3B5 is retail and SSDSA2CT040G3K5 is for resellers.
http://ark.intel.com/products/56568/Intel-SSD-320-Series-(40GB-2_5in-SATA-3Gbs-25nm-MLC)

 

I think you don't need to care much about the seq. speeds as a boot drive. I might be wrong tho .

 

A Windows 7 install is probably around 15GB, so stay away from the 20GB drive...

 

Sequential write speeds are only important for things like file transfers and video editing.

For booting, launching applications, installing the Intel 320 40GB with 45MB/sec write will feel as fast as any SSD.

 

Sequential speeds aren't really important at all. Consider the size of the largest files you use consistently. If you are like most people the files are smaller than 10 MB. At 200MB per second you'll open that file in 0.05 seconds, and at 400MB/s you will open that file in 0.025 seconds. Is that important to you?

If your work involves editing gargantuan picture files all day, then do the math and see if sequential performance makes a difference for you.

Otherwise, when are you transferring large sequential files? If you're copying files from one disk to another, then you can only possibly get those max SSD speeds if you are transferring across the bus from one SSD to the other. If you are transferring to or from a hard drive then you are limited by the pokey hard drive speed. If you are transferring to another SSD on USB, then you are limited to the pokey USB speed.