First off, if you are looking at buying this sander and the higher price really doesn't bother you too much, stop reading and buy the sander. You will not be disappointed.

For the rest of us that haven't discovered the money tree and the higher price is a concern, read on.

I have been restoring street rods for many years in my garage as time and/or money allow, and I have gone through several dual action sanders over the years. As a starving college student, I used the Campbel Hausfeld models because I could pick one up for around $30 and use it till it finally broke. I have owned several Craftsman models and some Chicago Pnuematics models as well. They all work fine if you don't mind sanding to the continual sound of your air compressor trying to keep up with it. In fact my CP sander was working OK till an F5 tornado sent it somewhere to find a new home (we never found it).

So as I have been building up my tool collection again, I am taking a different approach and trying to find the highest quality tool without just paying a premium for a name brand (Yes, I'm talking to you, Snap-On). I read a ton of reviews on several different brands (Dynabrade and IR Industrial, etc) and they generally had a common theme. People would say things like, "Well, it's not a Hutchins 3500, but it will do". After kicking it around for a few days my wonderful wife told me to just buy the sander and quit worrying about it. Actually, I think she is just in a hurry to the the 57 Bel Air on the road, but that is another story. So I pulled the trigger and have been using it for a little over a month now.

PROS:
1. This sander is quite a bit quieter than the previous sanders I have used. I have never had one that I felt I needed ear protection, but it is a nice plus.
2. The vibration of this sander is substantially less than any other sander that I have ever used. I have never used a Dynabrade so I can't compare those, but I can use the Hutchins for an extended period of time and it doesn't put my hand to sleep.
3. This sander uses substantially less air than cheaper models. I believe the specs show it at 11 CFM and I believe it. My compressor (Two Stage 80 gallon IR) will kick on for a few minutes and then kick off while I'm still sanding. I have never had a DA sander that a compressor could actually keep up with it. That is quite a pleasant change.
4. This sander has some substantial torque. I have never had the sander just stop because I applied pressure to it. Now, I don't apply much pressure when using a DA, but lesser sanders have slowed significantly while in use. I have my compressor set to around 85 PSI and this sander just keeps going.
5. I haven't had to change the pad yet, but I can tell the thumb lock button will be much more convenient than some other models I've used.

CONS:
1. This is less of a con than an explanation. If you should ever have to replace the pad on the sander, you have to replace it with a Hutchins pad and they are currently around $35. The reason for this is it is a balanced pad. This is one of the ways, the sander produces less vibration.
2. I keep hitting the trigger when replacing a disc because the the trigger covers most of the top of the sander. Some workarounds would be to get one of the optional handles or do like I do and just disconnect it when I'm changing pads.

Conclusion:
If this is going to be used for daily work, then this sander should be a must-have addition to your tool kit. I would put myself into the range of serious hobbyist. I am not a professional, but I am currently building two cars in my home shop. If you would put yourself in this range as well, then get the sander. If you have one project and don't plan on starting another one, save yourself some cash and get a cheaper sander. I have put a few cars on the road using a cheap CH sander.

Lastly:
I have read many reviews on this sander and understand that some people are extremely happy with the sander, but you have to manage your expectations. It is still just a sander. Yes, it does seem to cut through material faster than the cheaper models, but it is not an easy button. I am still staring down many hours worth of work sanding down the 40 Chevy, but at least I will still have feeling in my hands when I finish it.

Air control lever and the shaft lock make this incredibly user friendly. However the manufacturer states the warranty would be voided if you use a pad other than Hutchins. This is a little far fetched and unpractical. But an extremely nice and well built sander. No Harbor Freight junk!

This DA is absolutley perfect its quieter tgen any other da i have been around and doesnt vibrate at all compared to other da's i have used love it five stars

Before I bought a DA sander I tried everybody else's at work. Dynobrade vibrates too much and is loud, Ingersoll Rand (IR4151) same picture. Tried just about every kind until somebody let me use a Hutchins. Seriously it doesn't get better then this. This is the best DA out there and they last a lifetime. One of our techs had his for 30 years and it still works great. 4500 and 3500 is basically the same sander only the 3500 is lighter. They're both 3/32 orbit but trust me it knocks down bondo like you've never seen before. It's really quite and doesn't vibrate a lot. I use mine every day and I love it

I have had the chance to use this tool several time since I purchased it, Smooth & Quiet, just Perfect for a guy who is trying to fix My own mistakes, with a orange peel clear coat, Most of my pickup truck looks like Glass, the rest will real soon. - I will say HUTCHINS 3500 is the tool I needed - to correct my horrible basecoat/clearcoat touch up job - gives me confidence to try again - but to sand and wet sand my truck with this tool has made it like GLASS - I did cut and polish it with Menzerna and a Flex polisher after using the HUTCHINS 3500 - I love this Tool - "all from Amazon". I am pleased with every purchase - and the service I get is Great--------------Thanks