Gary,
I've got an SP101 and a M66 in .357. I really like them both.
The 66 is substantially larger than the SP, and heavier. The trigger feels smoother, even though I've dry fired the SP to an acceptable level. The rear sight on the 66 is adjustable, and the front sight is raised and orange. All in all, it is a much nicer revolver, and is more fun to shoot than the workmanlike SP101.
Don't get me wrong, I love the SP. It is my "beater", the one firearm I take with me on the roadtrips and backpacking, etc.
However, If I were to choose a "target" .357, I'd probably pick up an N-frame, either the 27 or 28. They are the original platform, as stated above, for the .357 cartridge, which was loaded much hotter originally than it is today. An N-frame revolver will withstand repeated firing of high pressure loads. The N-frame is bulkier, but it doesn't bother me. If you have the opportunity to handle one, check the cylinder and you will appreciate its massive design.
The 27 is the deluxe model, with many variations of sights available, in addition to a serrated top and deluxe finish. Originally, these revolvers came in an "eye popping" nickel blue, called "Magna Blue". Later Smith went to a black finish. I've seen these used for as little as $250 and up to $650 for "presentation" boxed weapons.
The 28 is the more affordable version, without so many options, but otherwise identical. I think they run about $200 to $275 and up for the good examples.
If you want to know more about the N-frame, you might check out the pistols section of Assaultweb.com, moderated by Dadduck, an avowed N-frame nut. He is eager to dole out info about these weapons.
Hope this helps!
Regards,
--
Brian
