You are probably really asking about the E-450, and it depends on a couple of things:
1. What seat got put into the motorhome? The E-450 and E-350 cutaway chassis with RV option package are shipped without seats, so the final vehicle manufacturer provides the seat, trimmed to match other interior fittings. If the RV manufacturer doesn't order the RV option package, the cutaway may come with an OEM E-series seat, XL or XLT trim.
2. How well does the seat fit you? At 5 1/2 feet, with short legs, the seat provided by Winnebago fit me quite well, but I find it a bit on the firm side. What works for me is that the seat is short enough for my short thighs, and just high enough that my lower legs are mostly upright. The fit and seating position was so good for me that I bought a E-series van, to replace the mid-size sedan that way stressing my back and tailbone by forcing me to sit in a legs-out semi-reclining position. The OEM seat construction, XLT trim, provides better comfortable support than the seat Winnebago put in my RV.
However, if you are tall, and have long legs, the van seat might not fit you so well. People with longer thighs,or those who like to sit reclined, might want a longer seat that supports more of their thighs.