There is a temptation to get talked up the sales escalator.
We may start looking at 20 HP tractors and by the time we get one all optioned up we're just about at the price of a 25, so we start adding the doo dadds to one of those and turn around to find a 30 for a few bux less.
Pretty soon we've gone right through Cat 0 and Cat 1 and this 65 HP thang with a heated cab and A/C seems to make so much sense (-:
So, how much power does one "WANT" vs "need" ?
Well it comes at a cost (Yeah, betcha didn't expect THAT part).
Just as a reminder that GREAT GOBS OF POWER aren't "needed", I found this thread today;
http://www.tractorbynet.com/forums/showthread.php?p=1840564#post1840564
I am not familiar with any of these "Garden" tractors, but it does SEEM that folk do turn soil with 'em and at a speed that is quite acceptable to "Gardeners" (I use the term with considerable respect).
BTW, these guys probably aren't compacting the soil very much (-:
BIGGER tractors - large homeowner size would pull 2 bottoms, maybe 3.
LARGE FARM tractors would pull 4 or 5, maybe 6.
If you have the time and are closer to Gardener scale than Agri-Biz scale a li'l 16 or 20 could do the job quite well - eventually.