I am a Race Tech user myself , I like what they offer and I like the fact that I can buy shims or any parts from them so I can do my suspension myself ... The only real difference from the 150R and RB is the swingarm is a bit longer on the RB and wheels are bigger , other than that it is basically the same bike , so specs would be the same , the reason I said 95 was because you were just trail riding/putting , so the bit more sag will help with comfort and not really take away from handling any , the 90 will make the bike a little nose heavy which would make it a slight bit twitchier (the stinkbug effect you often hear about , nose down rear high , which places more weight on the front which affects handling) , since I figured you just wanted to ride around and get comfortable on the bike , 95 would make it a little more forgiving ... and is still within specs ....
Once you gain more riding experience and get more aggressive with riding , you can raise the sag and work on cornering , etc. , but realistically , anywhere between 90-95 is fine , its all about what works or feels the best for you , go ahead and experiment , it won't hurt anything , and will give you a idea what the difference does , I find when track riding that some tracks work with more and/or less sag because of the type of dirt , corner shape , and how aggressive I am riding that track , for trail riding , I tend to prefer comfort and stability over handling preciseness , so I tend to run more sag , I vary (on a 450) between 100mm and 110mm , depending on where I am riding ... I am almost 60 (in Aug) , so for me comfort/plushness is a major factor in my ability to ride , especially when on a GP or MX track , the rougher the track , the more comfort I require , especially with a crushed , bone on bone left wrist , I have very limited left hand movement , so I feel every little hit , so suspension is critical for me , if I am to continue riding , especially MX , then I need to know what the bike does and why and how to make it work better , which is why I am so passionate about suspension , especially since I am riding a 17 year old bike with inferior suspension compared to current model bikes , so knowing what suspension does and how it affects the bike , is more important than most riders realize .............
Anyway , I tend to ramble as you may have noticed reading some of my posts (more like being anal about details and info) , on a side note , when I weighed 215 I still used the stock (5.5) shock spring on my 450X but used a 0.52 fork spring (which is how the bike still is set up and I bounce between 190-195 for weight right now) , but its about comfort for me on the trails , not handling , I also use a Kouba Link to lower the bike for trails so I can touch the ground (32 leg , so not easy to touch the ground in sketchy situations) , it does need to handle well enough to be safe , but I do not need preciseness to trail ride , as I won't be railing corners or berms with a 285 lbs bike , my R is sprung with a 0.48 fork springs and a 5.8 shock spring , I run that setup from 190-210 lbs , even though I only need a 0.47/5.7 for my weight , but the way I valved the suspension , I use the springs to hold up the bike in the stroke (which is how it should be done) and I revalved for comfort/handling , I use a 03 linkage to raise the rear , to help with cornering , and everyone that rides my R with the stiffer springs , remarks how comfortable it is compared to theirs with softer springs , but also how well it still handles ......... , sometimes stiffer is softer .........just some info you might use ...or not ....
The BBR springs are fine , just keep within the rate for your weight and you will be fine ...... I am far from a suspension expert , I know enough to get by with and hopefully help others along the way ... and I always am trying to learn more , as there is lots to learn ...