The 8 has better resale value.
8?s tend to have the higher priced engines, and more C/S props, and better instrument panels, so naturally in that sense their resale value should be higher because they have a heck of a lot more investment than the 4 guys who also are building from standard kits. Otherwise, you get more bang for your buck with the 4?s, and both planes will do just fine in their resale value.
When this was brought up a year ago, I did a barnstormers comparison of the 4?s and 8?s at the time, much of the lower prices of 4?s reflected that, but also the age of the 4?s which got a considerable jump on the 8?s. On the brief sample I took, the 4?s on average were about 11 years older than average than the 8?s. The 8?s were selling for about $30,000 more, but only because they had every bit of that extra kind of money invested in their plane which also tended to be newer and less hours also.
Here?s that link,
with post 30.
If you want a little(just a little) crisper handling and don't mind being a little more cramped go with the 4.
That does seem one of the biggest determining factors for a 4 vs an 8, is how big you and your passengers are going to be. At 5'10" and 157 lbs dripping wet, the 4 was a no-brainer for me, nor am I cramped. I realize I'll have to limit my passenger sizes to about 200 lbs in the back for my comfort level, although some I've heard have had 230 pounders back there, along with them being 200 lbs + up front. I've also read from another who flies with 1,700 lbs gross on his 4. I can understand concerns when the weights start approaching these limits, and why an 8 would then make a lot more sense for some people.