Biggest changes were in 2009. They went from batteries in the back to batteries in the front. The batteries in the front are nice and they make your boat more level. The drawback is they do slow your boat down a bit. With a 115 on a 620 I got right around 37 to 40 miles an hour with three guys. Currently I have a 150 Yamaha and I can get low 40s with 5-6 people no problem. If I put a different pitch prop I could easily get into the 50s but I’d have no low end.
I have had 4 Ranger 620 tillers. A 2001 a 2003 2007 and now currently a 2010. I liked every one of them. The storage seems to be much better than any other boat. And the ride is comparable to any good Glass boat.
I personally think you could buy any year 620T repower it and have a good boat for the next 20 years.
FWIW, I know of some musky guides that went with the skeeter from a ranger and went back to Ranger because Skeeter would not track very well in the water and also had a lot of pitch and roll when hit by waves while casting. They said the Ranger handled waves much better while casting.