I own both an X32 and just recently the DL32R.
It's hard to compare them, but for me it's easy to make them both sound great. I've used the X32 many times, and the DL32R only once, so take my opinion for what it's worth.
I don't know how the two mixers process the audio, but I have felt like the X32 was running out of headroom, as if it doesn't use 32-bit floating point DSP. As long as you keep the levels low, it's fine. On the DL32 I had the levels up relatively high and I never felt like it was running out of head room.
The reverbs are ok on both. People say they suck, but I guess I'm not that picky.
The preamps seem fine on both, not noisy and don't clip easily.
Which one can I make sound better? I don't want to sound incompetent, but if one is easier to use, then I can make it sound better. The Mackie is VERY easy to use, but has a very limited amount of DSP options. The X32 has more DSP options, but they are harder to insert in the heat of battle.
Tweaking the EQ or compression on Master fader is much faster than on the the X32 or its iPad app. Therefore, I can get better sound out of the Mackie.
My plan was to buy the DL32 for small events alone, and then on large scale events use it as a stage box with my X32. "There's no substitute for physical fasders" was my original thought. Now after being exclusively iPad for a weekend conference, I'm pretty sure I can live without the physical faders. Mackie really knocked it out of the park with the Master Fader design. Just be sure you have a current iPad! Old iPads suck with Master Fader. I used my Air 2 which felt perfect, my old iPad 2 with was REALLY sluggish, and an iPad Retena which was even worse than the older iPad 2.
As other have said, both mixers are budget products that perform well beyond their price point. With either mixer you have more power than was imaginable at even triple the price.
I think I can sell my X32, its case, the Dante card and little-lite for much more than the cost of the DL32. The X32 is great, but can't get it into my car in its case by myself. For that reason alone, I want to sell it. But it served me well, and sounded awesome, so It'll have a fond place in heart.
One little note about the DL1608... I have one of those too. The lack of digitally controlled mic pres really crippled that product, and the iPad recording let me down once. I never loved it like I do the DL32. If I can't get more then $300 for the DL1608, I'll keep it, but if it's worth more than that, I'll get rid of it too. I might even part ways with my dusty old, but still working Mackie 1642 VLZ. My wife will be very happy.
~Jay