• The institution of a sliding "Supertax" that would charge teams $2 in luxury tax for every dollar over $70 million in payroll, $3 for every dollar over $75 million in payroll and $4 for every dollar for teams with payrolls above $80 million
Like this in some form - really clamps down on overspending by big teams and aids in competitive balance
• A provision to allow each team to release one player via the so-called "amnesty" clause and gain both salary-cap and luxury-tax relief when that player's cap number is removed from the books
Meh - it's reducing the impact of making bad signings. This is an advantage for bigger market teams who can afford to eat their crappy contracts (and usually have more bad deals to begin with). But I'm sure the players are ok with it because it expands the money pool a lot next year.
• Shortening guaranteed contracts to a maximum of three or four seasons
Don't like it - I'd rather see 5. Too much player turnover this way. Imagine if "The Decision" happened every 3 years.

• Limiting Larry Bird rights -- which enable teams to exceed the salary cap to re-sign their own free agents -- to one player per team per season
Like it - makes teams prioritize but still gives the right to lock down their most important players.
• Reducing the annual mid-level exception, which was valued at $5.8 million last season, to roughly $3 million annually and limiting mid-level contracts to a maximum of two or three seasons in length as opposed to the current maximum of five seasons
Really like the drop in years (prefer 3), like the salary cut but would like to see less of one.
• A new "Carmelo Rule" that would prevent teams -- as the New York Knicks did in February with Anthony -- from using a Bird exception to sign or extend a player acquired by trade unless they are acquired before July 1 of the final season of the player's contract
Really, really like this one. No more skirting the Bird rules with mid-season acquisitions. I might like to see the deadline moved into the off-season free agent period, though. If you've got a guy for a full season you should be able to use Bird Rights. This would encourage teams with superstars who are likely to bolt (Denver, now Orlando) to move the guy in the offseason instead of shaking up the league midway through the year.
• The abolition of sign-and-trades and the bi-annual exception worth $2 million
Really like no sign-and-trades, would rather see the bi-annual stick around, especially as contract length drops and more players are in the free-agent mix each year.
• Significant reductions in maximum salaries and annual raises and a 5 percent rollbacks on current contracts
Ok with the first, really don't like the second. You wrote and signed the contract, live up to it. If they have to gradually work in the new system to deal with this, so be it.
There are also still some teams, sources say, who are pushing for some sort of franchise-tag system similar to what the NFL employs as well as a restriction that allows big spending teams to exceed the annual luxury-tax threshold only twice every five seasons.
Don't like the franchise tag at all, and the threshold rule seems like it'd be really tough to implement - if a team goes significantly over the threshold, it usually stays there for awhile (or guts the team to get under it).
I guess my biggest overall concern is with the reduction in deal length and cap exceptions creating a much more volatile league. Big, big free agent classes every year. Seems like it'd be a lot tougher to create a long-term core under these rules, and that's what I think a lot of fans respond to.