first oil draining is easy run mower for about 30 sec to a min pull the dipstick and lay on its side and out the filler tube gets all to oil and while its draining you can sharpen the blades.
i went from a hrx to an hrc and find it hard to use the hrx now it feels to light hated filling it up every lawn or to my commercial has a 2 litler tank and can get 5 - 6 lawns per tank compared to the one or 2 if lucky.
baging i found that i could usualy get about 3/4 bag till it would not suck any more the commercial will fill the bag and shoot then start to mulch.
i love the controls and the feel of both mowers they are long but im taller and that works beter for me.
i found the clip director would get grass in it and was hard to move from bag to mulch .
the hrx has a 6.5 hp and the commercial has a 5.5 hp i do notice a power diference in taller grass and that is probaly where you get the fuel acconemy.
i noticed the hrx tends to leave a small line of grass on the right side so having to overlap to get the left behind grass is hard to get nice lines.
over all is is a very nice mower but i will probaly go for a nother commercial spending that extra couple hundred is well worth it but either way you cant go wrong with any honda.
this is just my .02 cents and what i have found and my recomendations.