Depending on who you talk to, the 3576 is much improved over the 3575 in terms of its ATSC tuner. A great many 3575s were returned due to tuner problems, many obsessive
members here returning three or four units until they got one from a better production run. The 3576 is not being returned nearly as much, so there is a smaller pool of refurbs to draw from. Also, the Phillips 3575 was a "panic buy" many people ran for because there was no other good DVD/HDD recorder in stores at the time. That initial rush provided a lot of returns that we're not seeing with the 3576, which is not selling as well since that artificial initial demand was satisfied by the 3575. Current demand is so low Phillips has announced they're getting out of the DVD/HDD recorder business at the end of this year. We're lucky the 3576 is pretty good, because its the last such unit we will ever see sold in the USA: the cable/satellite integrated PVR has just totally killed mass-market interest in DVD recorders, even more the expensive models with HDD. This is not to say the 3576 is perfect, a number of people here still complain about ATSC tuner issues, but mostly with "clear" QAM cable channels.
On this topic I have to differ with the majority forum attitude: living in New York City (near Kennedy Airport), I've had to deal with venal, regulation-defiant cable systems that block subscribers who refuse to rent the decoder box at every turn. Anyone within 20 miles of New York City is considered delusional if they actually think they will get anything but the five broadcast networks and the weather channel thru cable without a decoder box. Not going to happen, FCC and local regulations be damned. For many, MANY communities in the USA, "ClearQAM" is a pipe dream: expecting an ATSC DVD recorder to magically free you from the decoder box is almost certain to disappoint. I certainly understand frugality or budget restraints or moral resistance to the cable companies, but this is not a realistic attitude. The cable conglomerates could give a rats ass whether you or the government think you have a right to clear digital cable without a box: they disagree and want to rent you the box. So they give lip service to QAM but mess with it to make it as dysfunctional as possible. This *may* change after the February 2009 switchover, but I wouldn't hold my breath assuming they'll act in good faith: usually they don't.
The Phillips 3576 is about as good a USA-specific DVD/HDD recorder we will ever see, and it will be gone soon. Periodically they go on sale for $249 at CostCo or other big-box stores: look for a sale and grab one while you still can. Don't get bent out of shape worrying about its ATSC performance: right now, nearly EVERY device with an ATSC tuner has issues. The 3576 is in the top half of the pack in terms of reception stability.