I am looking at trading my LNIB stock Gen4 G17 with 3 mags for a LNIB S&W M&P with 2 mags and night sights.  Do you think this would be an equal trade or would one have a little more value than the other?  Thanks.

If the M&P has a stock trigger you are on the losing end of the deal.  If you are decent with handtools, that can be fixed by messing with the sear.  Why do you want an M&P and why does he want a Glock?  M&P mag prices are astronomical so that is something to consider if you plan on getting more than the two it has.  To me, the Glock gives you many more options.  And its trigger pull can be adjusted with $5-15 parts.

I got rid of my M&P partly due to the trigger.

Also a Glock is easier to work on.

Yeah, I didn't give you guys a lot of background info.  I wanted to throw up the question quick before heading to work.  I already have a G35 so it seems a little redundant to have another full sized frame relegated to just 9mm.  I could keep one and go with extra slides and conversion barrels to get to 9mm.  I don't want to sell the G17 outright since I bought it before I knew squat about Glocks.  I paid more than blue label prices but less than full retail.  Lightly used they go for around $500 here so if I sold it outright I'd loose some money on it.  I thought trading even up for an M&P might be a better alternative.

I would say that is a pretty even trade.  A new M&P with 2 mags and standard sights can be had for $399 if you watch for the good sales. Add night sights to it and you are up to about what a Glock would be.
When M&Ps are new, triggers are gritty and creepy.  Shoot them some and they smooth out real nice. My stock M&P triggers are all BETTER than any of my stock Glock triggers.
M&Ps and Glocks are both great guns.

Here is the way I look at these trade deals.

If some one had a gun they didn't use or want and they took it to a dealer they would only get 60 to 70% of its retail value . That is how dealers pay the light bill and try to come out ahead a few bucks at the end of the week.

If two folks come into a deal and get rid of something they don't want and get something they want it is really a win/win deal.

Now I am a solid Glock guy and not a big fan of the M&P so I think the guy who is getting the Glock is doing better

Same. I don't know if mag production has increased since I had mine, but M&P9 mags were kind of hard to find.

I've had both. Got rid of the M&P for personal preference reasons. My opinion they are very similar guns. If your ok with the trade then go for it. The value seems close enough I wouldnt worry

That's probably a fair trade. Used Glocks bring a little more than used M&Ps around here, but the night sights balance it out. I like my M&P a lot, but I do prrefer a G17 at the end of the day.