The wife and I went through this same discussion......we chose the 190 over the 195....
The 190 has better fuel economy, and uses 87 instead of 93 octane fuel. The fuel burn calculations made (using fuel burn numbers from boattest.com) showed about $250/mo in additional fuel over a 12 month period assuming 100hrs/year, a price difference of about $0.75/gal, and a fuel burn difference of 2 gallons per hour (4 for the 190, 2 for the 195). Those are rough numbers, but you get the idea. The difference in fuel can be significant.
Capacity discussion.....We've had an 19ft class boat before (18'6" Rinker). 8 people on that boat was TOO CROWDED and not fun for anyone. When we decided that our "typical" load would most likely be 4 adults and 2-3 kids (two average families) we found that the 19' would be enough. 8 Adults on our 190 will be OK, but still crowded, and this is with the improved room in the Yamaha over our older Rinker. We've had 4 adults and 1 kid out already and it was plenty spacious, more adults at the raft up this past weekend quickly showed we were stuffed at 8 adults.
Power....The 195 offers more holeshot, and more top end......OK, when are you going to use more holeshot? With a heavy load, from our capacity discussion we had already ruled that out as a valid scenario. We're considering a typical load to be 7 passengers with 2-3 of those being children. So the use case for a heavy load and holeshot is gone. Now, lets look at top speed. Sure 50mph on the water is great, but when am I going to actually need/want to do that. I know from previous use that the family doesn't like much over 40, and really, we're never in a need to rush on the water that 35-40 isnt' going to cover us. The 190 covers that just fine.
Value.....The 190 lost this one. The 195 is an exceptional value for what you get. Upgraded speakers, bigger engine, bigger pump, platform turf, powder-coated windshield and tower. The extra $5k-ish here is definitely WORTH the money between the two. I think the guys with the 195 got a better bang for their boating buck than I did in terms of equipment.
In the end, it was the additional fuel burn without a real "need" for the power that really tipped the scales for us over to the 190 from the 195. We preferred the graphics and colors a little better on the 190 (little less aggressive to the wife), as well as the brushed tower and gray windshield over the black. They are the same length and weight essentially, so towing and storage was a wash between the two. So far we've been pleased with the performance of the 190.
I really think a good hard look at your intended usage, and how realistic that is will lead you to the right choice. You can hear from us all day long, but no two people use their boat the same, and that weighs VERY heavily in the decision.