IMHO - there is no comparison between one of the Asian made 15" planers and Chiu Ting Machinery produced Delta sold DW735. They are not designed for same market, or use.
1) Planers are designed for reducing thickness, not creating a finish ready surface.
Both machines are designed for thinning wood, but with different end goal.
-15" planer will run 8 hours a day, plane thousands of bdft of lumber between blade changes, and happily whack off 1/8" on 15" board at a tiime.
- Lunch box planer is made for intermittent use, needs new blades every 100-500 bdft, and struggles to remove more than 1/16" on full width cut.
2) Blade type - Straight or Helical:
Blade choices determine the quality of cut, lifetime of knives, and should be suited to your shop use profile.
- Regardless of machine; Straight blades create smoothest surface finish on majority of woods. Exception being heavily figured wood with many reverse grain changes. On figured woods; straight blades can/will have more tear out. There are some techniques to reduce the tear out, but rarely make it zero on highly figured wood.
Straight knives can be bought with tool steel edges or carbide. Carbide last longer, but can not be made as sharp as tool steel. When planning 'fuzzy' woods like cottonwood or palm, carbide will leave a rougher surface.
Lunch box planers (like DW735) with fresh sharp straight knives can make a finish ready surface thanks to very light cut depth. This makes hobbyist happy for initial stack of boards, as everyone hates sanding. But happiness fades as knives dull.
Repeat, reducing thickness, not creating a finish ready surface.
15" planers are designed for bigger bite and use segmented in feed roller with 'edges' to pull in rough cut lumber. When 15" planer set up for rough lumber to cut a thin pass, it tends to leave compression lines in top of board. The machine can be adjusted to minimize the witness lines, but few folks are willing to adjust 15" industrial planer during a all day run to solve this issue. Leaving the 15" planer set up for light cut, usually means rough lumber can have feeding issues. The range of setup options makes it less common for unknowing to achieve finish ready wood off the 15" planer, but not impossible.
Repeat, reducing thickness, not creating a finish ready surface.
- Helical heads use carbide knives that have longer life, but cut differently. Byrd Shellix heads cut at angle to reduce tear out issues on figured wood. Spherical heads cut small bite parallel to head, with cutter staggered from each other. Both helical types have less tear out issues with figured woods, but leave same finish as straight blade on straight grain wood.
Helical heads do not plane wood as smooth as straight blade. There are usually lines (often invisible to naked eye) on surface due the cutting angle of carbide cutters and row of different cutters. Most of time these lines don't show up until you apply some stain on un-sanded surface. Some units may not 'see' lines until helical head begins to wear, the lines become more pronounced. While the cutting edge may still be sharp the corner has worn enough to leave these planer tracks down the board.
Repeat, reducing thickness, not creating a finish ready surface.
3) IME -
The DW735 is small shop hobby planer, that can used everyday; but it guzzles blades like NFL fans drink beer - many during each event. Hated mine when I had it. Solution to DW735 blade life issue is adding a $500 helical head. Dewalt has even realized that daily planer users need better blades and they sell an OEM helical head version. Helical head on DW735 is a step backwards in value for hobby shop unless all you run in figured wood. The helical blades last longer, but the hidden lines require just as much or more sanding. The DW735 is also full of plastic moving parts that will not last your wood working lifetime. If you read the forums you will see reports of how DW735 plastic gears break with age and/or extended use.
BTW - The DW735 is not a true lunch box planer, you store under your bench easily. It weighs almost 100lbs and requires strong body/mind to pick it up and toss it under the bench. As soon as you put the DW735 on stand, it takes up nearly same floor space as 15" model; which means you there is little shop space savings over a more capable 15" planer.
Every shop should have a 15" planer.
If you regularly buy stacks of rough lumber, once you use the larger 15" planer; you will giggle like little girl with delight every time it is used. Sometimes I don't want to stop feeding it lumber, it is such a joy to use. They are low maintenance once set up. Shot of oil on the feed roller bearings every use, and gear box oil change once every year or three. They are hard to kill, and run for decades with proper care. Blades last forever compared to lunch box planer. Have rebuilt a couple of 30+ year old machines from professional shops, where a new set of bearings, new out feed roller; and they are ready for another 30 years of every day use.
Thanks for reading my opinion.
Best Luck finding a 15" planer.