Actually, the Sony's write time really isn't that bad. Also, I've heard that the F717 has absolutely NO shutter lag, just like a DSLR, which is really nice. The 7Hi has considerable shutter lag, I believe. Also, write time has been improved on the F717, and there is now USB 2.0 support in the camera, so pictures will transfer to the computer faster.
Go for the F717 if you want to, but deep down it's just a quicker F707 with a few bells and whistles - same lens, same sensor... But IMO, I would not buy the 7Hi.
I'll point out a few areas that the Sony F707 outperforms the 7Hi, and the F717 is even better.
1) Sony has a 3 megapixel mode, very nice if you don't need all 5 megapixels (I use it often) 7Hi has only a 5mp, then 2mp mode.
2) Sony macro focus range - 2cm. 7Hi - 13cm. You can get closer with the Sony.
3) Sony has a faster lens - f/2-2.4 - f/8. 7Hi is only f/2.8-3.5 - f/8. What this means is the Sony's aperture can open up wider, letting more light in, which means you can take low light pictures without having a long shutter speed.
4) Sony has Hologram autofocus (laser focusing), so you can get perfectly-focused pictures in pure darkness.
5) Sony has a Nightframing mode, an infrared mode that lets you compose a picture in pure darkness.
6) Sony has a Nightshot mode, which lets you take infrared pictures (in pure darkness)
7) 7Hi movie clips are limited to 60 seconds each.
8) Sony uses a small, "Infolithium" battery. 7Hi uses 4 NiMH AA batteries - pretty inconvenient.
9) 7Hi is bigger, bulkier than the Sony.
I won't be completely biased here, and tell you the 7Hi's stronger points.
1) F707 fastest shutter: 1/1000. 7Hi - 1/2000. But, F717 is also 1/2000.
2) F707 - no histogram. 7Hi - Live histogram. But, F717 has a live histogram. too.
3) F707/F717 zoom range - 38-190mm. 7Hi - 28-200mm. Extra 10mm on each end, not drastic.
4) F707 max ISO - 400. 7Hi - 800. But F717 max ISO - 800 too.
5) F707 doesn't have a hot shoe - 7Hi does. But F717 does too.
So there you have it, both sides of the story. Besides all that, the image quality from the Sonys is said to be the best in its class, and I have to agree.
If you want to do some more comparing here are the links:
Review by Phil Askey:
7Hi: Review hasn't been written yet.
Be sure to read the reviews. They give a ton of information about each camera, written by a professional, Phil Askey, and he let's you know his opinion of each camera as well.
Whew, that took a long time to type up. If you have any more questions, you can email me at firstname.lastname@example.org