I "upgraded" from the vivofit2 to the 235 and I'm seeing crazy high calories with the HR monitor turned on... Below are two examples... I have plenty more...
On 5/5 I used my vivofit and rhythm+ hrm (only when doing an activity) to record steps and a 30 min p90x3 yoga activity. I registered 12K steps and was given 279 active calories for that. I was given 178 calories for the 36 min yoga session. That gave me a total of 2462 calories for the day. That is what I'm used to seeing.
On 5/29, I used my 235 with the HRM turned on. I registered 13k steps and was given credit for 3993 active calories! I did a 33 min p90x3 "the challenge" session which is pullups and pushups and was given credit for 158 calories (slightly low). The total for the day is 5798 calories!
The active calorie and total counts since using the 235 are crazy high! The amount being synced to MFP is another topic all together...