Rangefinders are definitely a great tool to improving your game by giving you confidence in your club selection - which goes a long way in hitting a good shot.  Although adjusting yardage for slope is a nice feature, I personally don't think it is worth it because you are not allowed to use the slope feature in tournament competition.

Good luck with your purchase and hit'em well!

I love my rangefinder, and even though I've never used one with slope, I've never felt that I needed it.  I don't play in enough tournaments to worry about the "legality" of it, but in everyday rounds, I just simply don't think I need it.  Now, if I found one for a great price (thus taking price out of the equation) I wouldn't not buy it because of the slope feature.  But I wouldn't actively search out and pay more for the slope feature.

To me slope is a slight cheating aide.... In a laughing way.... It takes some of the sport out of it!

I would say yes because slope makes a difference in distance.  I always want to know how much slope affects my choice of club.  I found out knowing the slope changes what I choose to use in club.  I get closer!

I feel that a rangefinder with slope is nice if you are mapping out a course that you are going to play in a tournament that doesn't allow rangefinders. I would go with a regular rangefinder because it gets the job done and is legal for most tournament play. 

For those who have used a range finder with slope, has it even really helped you?  I just don't see it giving enough of an advantage to spend the extra money, especially for just a practice round.

I use one with slope, but I rarely take its reading over my own judgement. 

I say trial and error is a better option.

To answer your question, it depends on what you use your rangefinder for. Obviously, the rangefinders that convert between slope and no slope are the best. If you play in a lot of tournaments, I would go without slope because it is illegal in tournaments. If you plan on using it for casual rounds, slope is better because it makes the shots easier. It just depends if you want to pay more for the slope function.