While the Swifts remain to be an excellent pair of bins, a lot has changed in the way of binocular manufacture technology in the last 8-10 years.
There are numerous pairs to choose from in the price range you mention ($300-500). One thing I will caution, it is very important to handle the binoculars you wish to purchase before you buy. Many people have no second thoughts about buying sight unseen. You wouldn't buy a car without a test drive, right? And, in my opinion, the feel of the binocular is just as important as the optical quality. After all, you could have the finest glass and coatings in the world but if the bins don't feel good in the hand or are too heavy, you probably won't want to use them.
Aside from Swift, you might look into the following manufacturers who produce high quality optics in your price range; (in no particular order) Zeiss, Kowa, Vortex, Leupold, Bushnell, Minox, Steiner and Nikon. My guess is that you'll have twice as many makes and models to choose from in comparison to when you originally purchased your Swifts. One additional note; if you can make the jump to $600-800, there are some superb optics which rival the top end glass.
I second the earlier close focus comment. Birder's are continually finding the joys of butterfly watching. Just make sure the parallax is not too bad.
Hopefully this helps aid your decision just a little.
New Jersey Audubon Society
Cape May Bird Observatory
701 E. Lake Drive, P.O. Box 3
Cape May Point, NJ USA 08212-003
Ph: 609-884-2736 Fx: 609-884-6052
Take A Kid Birding®
Subject: another optics question
From: Kevin Cross <kevc AT GMAVT.NET>
Date: Tue, 4 Sep 2007 13:32:33 -0400
On the way to Algonquin last week, my beloved Swift Ultra Lites
(8x42, the old design, paid $200 about 8 years ago) were stolen from
our vehicle. I always thought the clarity and light-gathering of the
Swifts were as good as binos costing quite a bit more.
As I research a replacement, I'd love to hear what folks like in the
mid-range, say $300-500.
I'll be sure to check the archives for previous threads. Please
respond off-list if you prefer...